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Diffstat (limited to 'nx-X11/extras/Mesa/src/mesa/swrast/s_span.c')
| -rw-r--r-- | nx-X11/extras/Mesa/src/mesa/swrast/s_span.c | 1511 |
1 files changed, 1511 insertions, 0 deletions
diff --git a/nx-X11/extras/Mesa/src/mesa/swrast/s_span.c b/nx-X11/extras/Mesa/src/mesa/swrast/s_span.c new file mode 100644 index 000000000..47fa02bf1 --- /dev/null +++ b/nx-X11/extras/Mesa/src/mesa/swrast/s_span.c @@ -0,0 +1,1511 @@ +/* + * Mesa 3-D graphics library + * Version: 6.3 + * + * Copyright (C) 1999-2005 Brian Paul All Rights Reserved. + * + * Permission is hereby granted, free of charge, to any person obtaining a + * copy of this software and associated documentation files (the "Software"), + * to deal in the Software without restriction, including without limitation + * the rights to use, copy, modify, merge, publish, distribute, sublicense, + * and/or sell copies of the Software, and to permit persons to whom the + * Software is furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included + * in all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS + * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL + * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN + * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN + * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. + */ + + +/** + * \file swrast/s_span.c + * \brief Span processing functions used by all rasterization functions. + * This is where all the per-fragment tests are performed + * \author Brian Paul + */ + +#include "glheader.h" +#include "colormac.h" +#include "context.h" +#include "macros.h" +#include "imports.h" + +#include "s_atifragshader.h" +#include "s_alpha.h" +#include "s_blend.h" +#include "s_context.h" +#include "s_depth.h" +#include "s_fog.h" +#include "s_logic.h" +#include "s_masking.h" +#include "s_nvfragprog.h" +#include "s_span.h" +#include "s_stencil.h" +#include "s_texture.h" + + +/** + * Init span's Z interpolation values to the RasterPos Z. + * Used during setup for glDraw/CopyPixels. + */ +void +_swrast_span_default_z( GLcontext *ctx, struct sw_span *span ) +{ + const GLfloat depthMax = ctx->DrawBuffer->_DepthMaxF; + if (ctx->Visual.depthBits <= 16) + span->z = FloatToFixed(ctx->Current.RasterPos[2] * depthMax + 0.5F); + else + span->z = (GLint) (ctx->Current.RasterPos[2] * depthMax + 0.5F); + span->zStep = 0; + span->interpMask |= SPAN_Z; +} + + +/** + * Init span's fog interpolation values to the RasterPos fog. + * Used during setup for glDraw/CopyPixels. + */ +void +_swrast_span_default_fog( GLcontext *ctx, struct sw_span *span ) +{ + span->fog = _swrast_z_to_fogfactor(ctx, ctx->Current.RasterDistance); + span->fogStep = span->dfogdx = span->dfogdy = 0.0F; + span->interpMask |= SPAN_FOG; +} + + +/** + * Init span's rgba or index interpolation values to the RasterPos color. + * Used during setup for glDraw/CopyPixels. + */ +void +_swrast_span_default_color( GLcontext *ctx, struct sw_span *span ) +{ + if (ctx->Visual.rgbMode) { + GLchan r, g, b, a; + UNCLAMPED_FLOAT_TO_CHAN(r, ctx->Current.RasterColor[0]); + UNCLAMPED_FLOAT_TO_CHAN(g, ctx->Current.RasterColor[1]); + UNCLAMPED_FLOAT_TO_CHAN(b, ctx->Current.RasterColor[2]); + UNCLAMPED_FLOAT_TO_CHAN(a, ctx->Current.RasterColor[3]); +#if CHAN_TYPE == GL_FLOAT + span->red = r; + span->green = g; + span->blue = b; + span->alpha = a; +#else + span->red = IntToFixed(r); + span->green = IntToFixed(g); + span->blue = IntToFixed(b); + span->alpha = IntToFixed(a); +#endif + span->redStep = 0; + span->greenStep = 0; + span->blueStep = 0; + span->alphaStep = 0; + span->interpMask |= SPAN_RGBA; + } + else { + span->index = FloatToFixed(ctx->Current.RasterIndex); + span->indexStep = 0; + span->interpMask |= SPAN_INDEX; + } +} + + +/** + * Init span's texcoord interpolation values to the RasterPos texcoords. + * Used during setup for glDraw/CopyPixels. + */ +void +_swrast_span_default_texcoords( GLcontext *ctx, struct sw_span *span ) +{ + GLuint i; + for (i = 0; i < ctx->Const.MaxTextureUnits; i++) { + const GLfloat *tc = ctx->Current.RasterTexCoords[i]; + if (ctx->FragmentProgram._Active || ctx->ATIFragmentShader._Enabled) { + COPY_4V(span->tex[i], tc); + } + else if (tc[3] > 0.0F) { + /* use (s/q, t/q, r/q, 1) */ + span->tex[i][0] = tc[0] / tc[3]; + span->tex[i][1] = tc[1] / tc[3]; + span->tex[i][2] = tc[2] / tc[3]; + span->tex[i][3] = 1.0; + } + else { + ASSIGN_4V(span->tex[i], 0.0F, 0.0F, 0.0F, 1.0F); + } + ASSIGN_4V(span->texStepX[i], 0.0F, 0.0F, 0.0F, 0.0F); + ASSIGN_4V(span->texStepY[i], 0.0F, 0.0F, 0.0F, 0.0F); + } + span->interpMask |= SPAN_TEXTURE; +} + + +/* Fill in the span.color.rgba array from the interpolation values */ +static void +interpolate_colors(GLcontext *ctx, struct sw_span *span) +{ + const GLuint n = span->end; + GLchan (*rgba)[4] = span->array->rgba; + GLuint i; + (void) ctx; + + ASSERT((span->interpMask & SPAN_RGBA) && + !(span->arrayMask & SPAN_RGBA)); + + if (span->interpMask & SPAN_FLAT) { + /* constant color */ + GLchan color[4]; + color[RCOMP] = FixedToChan(span->red); + color[GCOMP] = FixedToChan(span->green); + color[BCOMP] = FixedToChan(span->blue); + color[ACOMP] = FixedToChan(span->alpha); + for (i = 0; i < n; i++) { + COPY_CHAN4(span->array->rgba[i], color); + } + } + else { + /* interpolate */ +#if CHAN_TYPE == GL_FLOAT + GLfloat r = span->red; + GLfloat g = span->green; + GLfloat b = span->blue; + GLfloat a = span->alpha; + const GLfloat dr = span->redStep; + const GLfloat dg = span->greenStep; + const GLfloat db = span->blueStep; + const GLfloat da = span->alphaStep; +#else + GLfixed r = span->red; + GLfixed g = span->green; + GLfixed b = span->blue; + GLfixed a = span->alpha; + const GLint dr = span->redStep; + const GLint dg = span->greenStep; + const GLint db = span->blueStep; + const GLint da = span->alphaStep; +#endif + for (i = 0; i < n; i++) { + rgba[i][RCOMP] = FixedToChan(r); + rgba[i][GCOMP] = FixedToChan(g); + rgba[i][BCOMP] = FixedToChan(b); + rgba[i][ACOMP] = FixedToChan(a); + r += dr; + g += dg; + b += db; + a += da; + } + } + span->arrayMask |= SPAN_RGBA; +} + + +/* Fill in the span.color.index array from the interpolation values */ +static void +interpolate_indexes(GLcontext *ctx, struct sw_span *span) +{ + GLfixed index = span->index; + const GLint indexStep = span->indexStep; + const GLuint n = span->end; + GLuint *indexes = span->array->index; + GLuint i; + (void) ctx; + ASSERT((span->interpMask & SPAN_INDEX) && + !(span->arrayMask & SPAN_INDEX)); + + if ((span->interpMask & SPAN_FLAT) || (indexStep == 0)) { + /* constant color */ + index = FixedToInt(index); + for (i = 0; i < n; i++) { + indexes[i] = index; + } + } + else { + /* interpolate */ + for (i = 0; i < n; i++) { + indexes[i] = FixedToInt(index); + index += indexStep; + } + } + span->arrayMask |= SPAN_INDEX; + span->interpMask &= ~SPAN_INDEX; +} + + +/* Fill in the span.->array->spec array from the interpolation values */ +static void +interpolate_specular(GLcontext *ctx, struct sw_span *span) +{ + (void) ctx; + if (span->interpMask & SPAN_FLAT) { + /* constant color */ + const GLchan r = FixedToChan(span->specRed); + const GLchan g = FixedToChan(span->specGreen); + const GLchan b = FixedToChan(span->specBlue); + GLuint i; + for (i = 0; i < span->end; i++) { + span->array->spec[i][RCOMP] = r; + span->array->spec[i][GCOMP] = g; + span->array->spec[i][BCOMP] = b; + } + } + else { + /* interpolate */ +#if CHAN_TYPE == GL_FLOAT + GLfloat r = span->specRed; + GLfloat g = span->specGreen; + GLfloat b = span->specBlue; +#else + GLfixed r = span->specRed; + GLfixed g = span->specGreen; + GLfixed b = span->specBlue; +#endif + GLuint i; + for (i = 0; i < span->end; i++) { + span->array->spec[i][RCOMP] = FixedToChan(r); + span->array->spec[i][GCOMP] = FixedToChan(g); + span->array->spec[i][BCOMP] = FixedToChan(b); + r += span->specRedStep; + g += span->specGreenStep; + b += span->specBlueStep; + } + } + span->arrayMask |= SPAN_SPEC; +} + + +/* Fill in the span.array.fog values from the interpolation values */ +static void +interpolate_fog(const GLcontext *ctx, struct sw_span *span) +{ + GLfloat *fog = span->array->fog; + const GLfloat fogStep = span->fogStep; + GLfloat fogCoord = span->fog; + const GLuint haveW = (span->interpMask & SPAN_W); + const GLfloat wStep = haveW ? span->dwdx : 0.0F; + GLfloat w = haveW ? span->w : 1.0F; + GLuint i; + for (i = 0; i < span->end; i++) { + fog[i] = fogCoord / w; + fogCoord += fogStep; + w += wStep; + } + span->arrayMask |= SPAN_FOG; +} + + +/* Fill in the span.zArray array from the interpolation values */ +void +_swrast_span_interpolate_z( const GLcontext *ctx, struct sw_span *span ) +{ + const GLuint n = span->end; + GLuint i; + + ASSERT((span->interpMask & SPAN_Z) && + !(span->arrayMask & SPAN_Z)); + + if (ctx->Visual.depthBits <= 16) { + GLfixed zval = span->z; + GLdepth *z = span->array->z; + for (i = 0; i < n; i++) { + z[i] = FixedToInt(zval); + zval += span->zStep; + } + } + else { + /* Deep Z buffer, no fixed->int shift */ + GLfixed zval = span->z; + GLdepth *z = span->array->z; + for (i = 0; i < n; i++) { + z[i] = zval; + zval += span->zStep; + } + } + span->interpMask &= ~SPAN_Z; + span->arrayMask |= SPAN_Z; +} + + +/* + * This the ideal solution, as given in the OpenGL spec. + */ +#if 0 +static GLfloat +compute_lambda(GLfloat dsdx, GLfloat dsdy, GLfloat dtdx, GLfloat dtdy, + GLfloat dqdx, GLfloat dqdy, GLfloat texW, GLfloat texH, + GLfloat s, GLfloat t, GLfloat q, GLfloat invQ) +{ + GLfloat dudx = texW * ((s + dsdx) / (q + dqdx) - s * invQ); + GLfloat dvdx = texH * ((t + dtdx) / (q + dqdx) - t * invQ); + GLfloat dudy = texW * ((s + dsdy) / (q + dqdy) - s * invQ); + GLfloat dvdy = texH * ((t + dtdy) / (q + dqdy) - t * invQ); + GLfloat x = SQRTF(dudx * dudx + dvdx * dvdx); + GLfloat y = SQRTF(dudy * dudy + dvdy * dvdy); + GLfloat rho = MAX2(x, y); + GLfloat lambda = LOG2(rho); + return lambda; +} +#endif + + +/* + * This is a faster approximation + */ +GLfloat +_swrast_compute_lambda(GLfloat dsdx, GLfloat dsdy, GLfloat dtdx, GLfloat dtdy, + GLfloat dqdx, GLfloat dqdy, GLfloat texW, GLfloat texH, + GLfloat s, GLfloat t, GLfloat q, GLfloat invQ) +{ + GLfloat dsdx2 = (s + dsdx) / (q + dqdx) - s * invQ; + GLfloat dtdx2 = (t + dtdx) / (q + dqdx) - t * invQ; + GLfloat dsdy2 = (s + dsdy) / (q + dqdy) - s * invQ; + GLfloat dtdy2 = (t + dtdy) / (q + dqdy) - t * invQ; + GLfloat maxU, maxV, rho, lambda; + dsdx2 = FABSF(dsdx2); + dsdy2 = FABSF(dsdy2); + dtdx2 = FABSF(dtdx2); + dtdy2 = FABSF(dtdy2); + maxU = MAX2(dsdx2, dsdy2) * texW; + maxV = MAX2(dtdx2, dtdy2) * texH; + rho = MAX2(maxU, maxV); + lambda = LOG2(rho); + return lambda; +} + + +/** + * Fill in the span.texcoords array from the interpolation values. + * Note: in the places where we divide by Q (or mult by invQ) we're + * really doing two things: perspective correction and texcoord + * projection. Remember, for texcoord (s,t,r,q) we need to index + * texels with (s/q, t/q, r/q). + * If we're using a fragment program, we never do the division + * for texcoord projection. That's done by the TXP instruction + * or user-written code. + */ +static void +interpolate_texcoords(GLcontext *ctx, struct sw_span *span) +{ + ASSERT(span->interpMask & SPAN_TEXTURE); + ASSERT(!(span->arrayMask & SPAN_TEXTURE)); + + if (ctx->Texture._EnabledCoordUnits > 1) { + /* multitexture */ + GLuint u; + span->arrayMask |= SPAN_TEXTURE; + for (u = 0; u < ctx->Const.MaxTextureUnits; u++) { + if (ctx->Texture._EnabledCoordUnits & (1 << u)) { + const struct gl_texture_object *obj =ctx->Texture.Unit[u]._Current; + GLfloat texW, texH; + GLboolean needLambda; + if (obj) { + const struct gl_texture_image *img = obj->Image[0][obj->BaseLevel]; + needLambda = (obj->MinFilter != obj->MagFilter) + || ctx->FragmentProgram._Active; + texW = img->WidthScale; + texH = img->HeightScale; + } + else { + /* using a fragment program */ + texW = 1.0; + texH = 1.0; + needLambda = GL_FALSE; + } + if (needLambda) { + GLfloat (*texcoord)[4] = span->array->texcoords[u]; + GLfloat *lambda = span->array->lambda[u]; + const GLfloat dsdx = span->texStepX[u][0]; + const GLfloat dsdy = span->texStepY[u][0]; + const GLfloat dtdx = span->texStepX[u][1]; + const GLfloat dtdy = span->texStepY[u][1]; + const GLfloat drdx = span->texStepX[u][2]; + const GLfloat dqdx = span->texStepX[u][3]; + const GLfloat dqdy = span->texStepY[u][3]; + GLfloat s = span->tex[u][0]; + GLfloat t = span->tex[u][1]; + GLfloat r = span->tex[u][2]; + GLfloat q = span->tex[u][3]; + GLuint i; + if (ctx->FragmentProgram._Active) { + /* do perspective correction but don't divide s, t, r by q */ + const GLfloat dwdx = span->dwdx; + GLfloat w = span->w; + for (i = 0; i < span->end; i++) { + const GLfloat invW = 1.0F / w; + texcoord[i][0] = s * invW; + texcoord[i][1] = t * invW; + texcoord[i][2] = r * invW; + texcoord[i][3] = q * invW; + lambda[i] = _swrast_compute_lambda(dsdx, dsdy, dtdx, dtdy, + dqdx, dqdy, texW, texH, + s, t, q, invW); + s += dsdx; + t += dtdx; + r += drdx; + q += dqdx; + w += dwdx; + } + + } + else { + for (i = 0; i < span->end; i++) { + const GLfloat invQ = (q == 0.0F) ? 1.0F : (1.0F / q); + texcoord[i][0] = s * invQ; + texcoord[i][1] = t * invQ; + texcoord[i][2] = r * invQ; + texcoord[i][3] = q; + lambda[i] = _swrast_compute_lambda(dsdx, dsdy, dtdx, dtdy, + dqdx, dqdy, texW, texH, + s, t, q, invQ); + s += dsdx; + t += dtdx; + r += drdx; + q += dqdx; + } + } + span->arrayMask |= SPAN_LAMBDA; + } + else { + GLfloat (*texcoord)[4] = span->array->texcoords[u]; + GLfloat *lambda = span->array->lambda[u]; + const GLfloat dsdx = span->texStepX[u][0]; + const GLfloat dtdx = span->texStepX[u][1]; + const GLfloat drdx = span->texStepX[u][2]; + const GLfloat dqdx = span->texStepX[u][3]; + GLfloat s = span->tex[u][0]; + GLfloat t = span->tex[u][1]; + GLfloat r = span->tex[u][2]; + GLfloat q = span->tex[u][3]; + GLuint i; + if (ctx->FragmentProgram._Active) { + /* do perspective correction but don't divide s, t, r by q */ + const GLfloat dwdx = span->dwdx; + GLfloat w = span->w; + for (i = 0; i < span->end; i++) { + const GLfloat invW = 1.0F / w; + texcoord[i][0] = s * invW; + texcoord[i][1] = t * invW; + texcoord[i][2] = r * invW; + texcoord[i][3] = q * invW; + lambda[i] = 0.0; + s += dsdx; + t += dtdx; + r += drdx; + q += dqdx; + w += dwdx; + } + } + else if (dqdx == 0.0F) { + /* Ortho projection or polygon's parallel to window X axis */ + const GLfloat invQ = (q == 0.0F) ? 1.0F : (1.0F / q); + for (i = 0; i < span->end; i++) { + texcoord[i][0] = s * invQ; + texcoord[i][1] = t * invQ; + texcoord[i][2] = r * invQ; + texcoord[i][3] = q; + lambda[i] = 0.0; + s += dsdx; + t += dtdx; + r += drdx; + } + } + else { + for (i = 0; i < span->end; i++) { + const GLfloat invQ = (q == 0.0F) ? 1.0F : (1.0F / q); + texcoord[i][0] = s * invQ; + texcoord[i][1] = t * invQ; + texcoord[i][2] = r * invQ; + texcoord[i][3] = q; + lambda[i] = 0.0; + s += dsdx; + t += dtdx; + r += drdx; + q += dqdx; + } + } + } /* lambda */ + } /* if */ + } /* for */ + } + else { + /* single texture */ + const struct gl_texture_object *obj = ctx->Texture.Unit[0]._Current; + GLfloat texW, texH; + GLboolean needLambda; + if (obj) { + const struct gl_texture_image *img = obj->Image[0][obj->BaseLevel]; + needLambda = (obj->MinFilter != obj->MagFilter) + || ctx->FragmentProgram._Active; + texW = (GLfloat) img->WidthScale; + texH = (GLfloat) img->HeightScale; + } + else { + needLambda = GL_FALSE; + texW = texH = 1.0; + } + span->arrayMask |= SPAN_TEXTURE; + if (needLambda) { + /* just texture unit 0, with lambda */ + GLfloat (*texcoord)[4] = span->array->texcoords[0]; + GLfloat *lambda = span->array->lambda[0]; + const GLfloat dsdx = span->texStepX[0][0]; + const GLfloat dsdy = span->texStepY[0][0]; + const GLfloat dtdx = span->texStepX[0][1]; + const GLfloat dtdy = span->texStepY[0][1]; + const GLfloat drdx = span->texStepX[0][2]; + const GLfloat dqdx = span->texStepX[0][3]; + const GLfloat dqdy = span->texStepY[0][3]; + GLfloat s = span->tex[0][0]; + GLfloat t = span->tex[0][1]; + GLfloat r = span->tex[0][2]; + GLfloat q = span->tex[0][3]; + GLuint i; + if (ctx->FragmentProgram._Active) { + /* do perspective correction but don't divide s, t, r by q */ + const GLfloat dwdx = span->dwdx; + GLfloat w = span->w; + for (i = 0; i < span->end; i++) { + const GLfloat invW = 1.0F / w; + texcoord[i][0] = s * invW; + texcoord[i][1] = t * invW; + texcoord[i][2] = r * invW; + texcoord[i][3] = q * invW; + lambda[i] = _swrast_compute_lambda(dsdx, dsdy, dtdx, dtdy, + dqdx, dqdy, texW, texH, + s, t, q, invW); + s += dsdx; + t += dtdx; + r += drdx; + q += dqdx; + w += dwdx; + } + } + else { + /* tex.c */ + for (i = 0; i < span->end; i++) { + const GLfloat invQ = (q == 0.0F) ? 1.0F : (1.0F / q); + lambda[i] = _swrast_compute_lambda(dsdx, dsdy, dtdx, dtdy, + dqdx, dqdy, texW, texH, + s, t, q, invQ); + texcoord[i][0] = s * invQ; + texcoord[i][1] = t * invQ; + texcoord[i][2] = r * invQ; + texcoord[i][3] = q; + s += dsdx; + t += dtdx; + r += drdx; + q += dqdx; + } + } + span->arrayMask |= SPAN_LAMBDA; + } + else { + /* just texture 0, without lambda */ + GLfloat (*texcoord)[4] = span->array->texcoords[0]; + const GLfloat dsdx = span->texStepX[0][0]; + const GLfloat dtdx = span->texStepX[0][1]; + const GLfloat drdx = span->texStepX[0][2]; + const GLfloat dqdx = span->texStepX[0][3]; + GLfloat s = span->tex[0][0]; + GLfloat t = span->tex[0][1]; + GLfloat r = span->tex[0][2]; + GLfloat q = span->tex[0][3]; + GLuint i; + if (ctx->FragmentProgram._Active) { + /* do perspective correction but don't divide s, t, r by q */ + const GLfloat dwdx = span->dwdx; + GLfloat w = span->w; + for (i = 0; i < span->end; i++) { + const GLfloat invW = 1.0F / w; + texcoord[i][0] = s * invW; + texcoord[i][1] = t * invW; + texcoord[i][2] = r * invW; + texcoord[i][3] = q * invW; + s += dsdx; + t += dtdx; + r += drdx; + q += dqdx; + w += dwdx; + } + } + else if (dqdx == 0.0F) { + /* Ortho projection or polygon's parallel to window X axis */ + const GLfloat invQ = (q == 0.0F) ? 1.0F : (1.0F / q); + for (i = 0; i < span->end; i++) { + texcoord[i][0] = s * invQ; + texcoord[i][1] = t * invQ; + texcoord[i][2] = r * invQ; + texcoord[i][3] = q; + s += dsdx; + t += dtdx; + r += drdx; + } + } + else { + for (i = 0; i < span->end; i++) { + const GLfloat invQ = (q == 0.0F) ? 1.0F : (1.0F / q); + texcoord[i][0] = s * invQ; + texcoord[i][1] = t * invQ; + texcoord[i][2] = r * invQ; + texcoord[i][3] = q; + s += dsdx; + t += dtdx; + r += drdx; + q += dqdx; + } + } + } + } +} + + +/** + * Apply the current polygon stipple pattern to a span of pixels. + */ +static void +stipple_polygon_span( GLcontext *ctx, struct sw_span *span ) +{ + const GLuint highbit = 0x80000000; + const GLuint stipple = ctx->PolygonStipple[span->y % 32]; + GLubyte *mask = span->array->mask; + GLuint i, m; + + ASSERT(ctx->Polygon.StippleFlag); + ASSERT((span->arrayMask & SPAN_XY) == 0); + + m = highbit >> (GLuint) (span->x % 32); + + for (i = 0; i < span->end; i++) { + if ((m & stipple) == 0) { + mask[i] = 0; + } + m = m >> 1; + if (m == 0) { + m = highbit; + } + } + span->writeAll = GL_FALSE; +} + + +/** + * Clip a pixel span to the current buffer/window boundaries: + * DrawBuffer->_Xmin, _Xmax, _Ymin, _Ymax. This will accomplish + * window clipping and scissoring. + * Return: GL_TRUE some pixels still visible + * GL_FALSE nothing visible + */ +static GLuint +clip_span( GLcontext *ctx, struct sw_span *span ) +{ + const GLint xmin = ctx->DrawBuffer->_Xmin; + const GLint xmax = ctx->DrawBuffer->_Xmax; + const GLint ymin = ctx->DrawBuffer->_Ymin; + const GLint ymax = ctx->DrawBuffer->_Ymax; + + if (span->arrayMask & SPAN_XY) { + /* arrays of x/y pixel coords */ + const GLint *x = span->array->x; + const GLint *y = span->array->y; + const GLint n = span->end; + GLubyte *mask = span->array->mask; + GLint i; + if (span->arrayMask & SPAN_MASK) { + /* note: using & intead of && to reduce branches */ + for (i = 0; i < n; i++) { + mask[i] &= (x[i] >= xmin) & (x[i] < xmax) + & (y[i] >= ymin) & (y[i] < ymax); + } + } + else { + /* note: using & intead of && to reduce branches */ + for (i = 0; i < n; i++) { + mask[i] = (x[i] >= xmin) & (x[i] < xmax) + & (y[i] >= ymin) & (y[i] < ymax); + } + } + return GL_TRUE; /* some pixels visible */ + } + else { + /* horizontal span of pixels */ + const GLint x = span->x; + const GLint y = span->y; + const GLint n = span->end; + + /* Trivial rejection tests */ + if (y < ymin || y >= ymax || x + n <= xmin || x >= xmax) { + span->end = 0; + return GL_FALSE; /* all pixels clipped */ + } + + /* Clip to the left */ + if (x < xmin) { + ASSERT(x + n > xmin); + span->writeAll = GL_FALSE; + _mesa_bzero(span->array->mask, (xmin - x) * sizeof(GLubyte)); + } + + /* Clip to right */ + if (x + n > xmax) { + ASSERT(x < xmax); + span->end = xmax - x; + } + + return GL_TRUE; /* some pixels visible */ + } +} + + +/** + * Apply all the per-fragment opertions to a span of color index fragments + * and write them to the enabled color drawbuffers. + * The 'span' parameter can be considered to be const. Note that + * span->interpMask and span->arrayMask may be changed but will be restored + * to their original values before returning. + */ +void +_swrast_write_index_span( GLcontext *ctx, struct sw_span *span) +{ + const SWcontext *swrast = SWRAST_CONTEXT(ctx); + const struct gl_framebuffer *fb = ctx->DrawBuffer; + const GLuint output = 0; + const GLuint origInterpMask = span->interpMask; + const GLuint origArrayMask = span->arrayMask; + GLuint buf; + + ASSERT(span->end <= MAX_WIDTH); + ASSERT(span->primitive == GL_POINT || span->primitive == GL_LINE || + span->primitive == GL_POLYGON || span->primitive == GL_BITMAP); + ASSERT((span->interpMask | span->arrayMask) & SPAN_INDEX); + ASSERT((span->interpMask & span->arrayMask) == 0); + + if (span->arrayMask & SPAN_MASK) { + /* mask was initialized by caller, probably glBitmap */ + span->writeAll = GL_FALSE; + } + else { + _mesa_memset(span->array->mask, 1, span->end); + span->writeAll = GL_TRUE; + } + + /* Clipping */ + if ((swrast->_RasterMask & CLIP_BIT) || (span->primitive != GL_POLYGON)) { + if (!clip_span(ctx, span)) { + return; + } + } + + /* Depth bounds test */ + if (ctx->Depth.BoundsTest && ctx->Visual.depthBits > 0) { + if (!_swrast_depth_bounds_test(ctx, span)) { + return; + } + } + +#ifdef DEBUG + /* Make sure all fragments are within window bounds */ + if (span->arrayMask & SPAN_XY) { + GLuint i; + for (i = 0; i < span->end; i++) { + if (span->array->mask[i]) { + assert(span->array->x[i] >= ctx->DrawBuffer->_Xmin); + assert(span->array->x[i] < ctx->DrawBuffer->_Xmax); + assert(span->array->y[i] >= ctx->DrawBuffer->_Ymin); + assert(span->array->y[i] < ctx->DrawBuffer->_Ymax); + } + } + } +#endif + + /* Polygon Stippling */ + if (ctx->Polygon.StippleFlag && span->primitive == GL_POLYGON) { + stipple_polygon_span(ctx, span); + } + + /* Stencil and Z testing */ + if (ctx->Depth.Test || ctx->Stencil.Enabled) { + if (span->interpMask & SPAN_Z) + _swrast_span_interpolate_z(ctx, span); + + if (ctx->Stencil.Enabled) { + if (!_swrast_stencil_and_ztest_span(ctx, span)) { + span->arrayMask = origArrayMask; + return; + } + } + else { + ASSERT(ctx->Depth.Test); + if (!_swrast_depth_test_span(ctx, span)) { + span->interpMask = origInterpMask; + span->arrayMask = origArrayMask; + return; + } + } + } + + /* if we get here, something passed the depth test */ + if (ctx->Depth.OcclusionTest) { + ctx->OcclusionResult = GL_TRUE; + } + +#if FEATURE_ARB_occlusion_query + if (ctx->Occlusion.Active) { + /* update count of 'passed' fragments */ + GLuint i; + for (i = 0; i < span->end; i++) + ctx->Occlusion.PassedCounter += span->array->mask[i]; + } +#endif + + /* we have to wait until after occlusion to do this test */ + if (ctx->Color.DrawBuffer == GL_NONE || ctx->Color.IndexMask == 0) { + /* write no pixels */ + span->arrayMask = origArrayMask; + return; + } + + /* Interpolate the color indexes if needed */ + if (swrast->_FogEnabled || + ctx->Color.IndexLogicOpEnabled || + ctx->Color.IndexMask != 0xffffffff || + (span->arrayMask & SPAN_COVERAGE)) { + if (span->interpMask & SPAN_INDEX) { + interpolate_indexes(ctx, span); + } + } + + /* Fog */ + if (swrast->_FogEnabled) { + _swrast_fog_ci_span(ctx, span); + } + + /* Antialias coverage application */ + if (span->arrayMask & SPAN_COVERAGE) { + const GLfloat *coverage = span->array->coverage; + GLuint *index = span->array->index; + GLuint i; + for (i = 0; i < span->end; i++) { + ASSERT(coverage[i] < 16); + index[i] = (index[i] & ~0xf) | ((GLuint) coverage[i]); + } + } + + /* Loop over drawing buffers */ + for (buf = 0; buf < fb->_NumColorDrawBuffers[output]; buf++) { + struct gl_renderbuffer *rb = fb->_ColorDrawBuffers[output][buf]; + GLuint indexTemp[MAX_WIDTH], *index32; + + ASSERT(rb->_BaseFormat == GL_COLOR_INDEX); + + if (ctx->Color.IndexLogicOpEnabled || + ctx->Color.IndexMask != 0xffffffff) { + /* make copy of incoming indexes */ + MEMCPY(indexTemp, span->array->index, span->end * sizeof(GLuint)); + + if (ctx->Color.IndexLogicOpEnabled) { + _swrast_logicop_ci_span(ctx, rb, span, indexTemp); + } + + if (ctx->Color.IndexMask != 0xffffffff) { + _swrast_mask_ci_span(ctx, rb, span, indexTemp); + } + index32 = indexTemp; + } + else { + index32 = span->array->index; + } + + if ((span->interpMask & SPAN_INDEX) && span->indexStep == 0) { + /* all fragments have same color index */ + GLubyte index8; + GLushort index16; + GLuint index32; + void *value; + + if (rb->DataType == GL_UNSIGNED_BYTE) { + index8 = FixedToInt(span->index); + value = &index8; + } + else if (rb->DataType == GL_UNSIGNED_SHORT) { + index16 = FixedToInt(span->index); + value = &index16; + } + else { + ASSERT(rb->DataType == GL_UNSIGNED_INT); + index32 = FixedToInt(span->index); + value = &index32; + } + + if (span->arrayMask & SPAN_XY) { + rb->PutMonoValues(ctx, rb, span->end, span->array->x, + span->array->y, value, span->array->mask); + } + else { + rb->PutMonoRow(ctx, rb, span->end, span->x, span->y, + value, span->array->mask); + } + } + else { + /* each fragment is a different color */ + GLubyte index8[MAX_WIDTH]; + GLushort index16[MAX_WIDTH]; + void *values; + + if (rb->DataType == GL_UNSIGNED_BYTE) { + GLuint k; + for (k = 0; k < span->end; k++) { + index8[k] = (GLubyte) index32[k]; + } + values = index8; + } + else if (rb->DataType == GL_UNSIGNED_SHORT) { + GLuint k; + for (k = 0; k < span->end; k++) { + index16[k] = (GLushort) index32[k]; + } + values = index16; + } + else { + ASSERT(rb->DataType == GL_UNSIGNED_INT); + values = index32; + } + + if (span->arrayMask & SPAN_XY) { + rb->PutValues(ctx, rb, span->end, span->array->x, span->array->y, + values, span->array->mask); + } + else { + rb->PutRow(ctx, rb, span->end, span->x, span->y, + values, span->array->mask); + } + } + } + +#if OLD_RENDERBUFFER + /* restore default dest buffer */ + _swrast_use_draw_buffer(ctx); +#endif + + span->interpMask = origInterpMask; + span->arrayMask = origArrayMask; +} + + +/** + * Add specular color to base color. This is used only when + * GL_LIGHT_MODEL_COLOR_CONTROL = GL_SEPARATE_SPECULAR_COLOR. + */ +static void +add_colors(GLuint n, GLchan rgba[][4], GLchan specular[][4] ) +{ + GLuint i; + for (i = 0; i < n; i++) { +#if CHAN_TYPE == GL_FLOAT + /* no clamping */ + rgba[i][RCOMP] += specular[i][RCOMP]; + rgba[i][GCOMP] += specular[i][GCOMP]; + rgba[i][BCOMP] += specular[i][BCOMP]; +#else + GLint r = rgba[i][RCOMP] + specular[i][RCOMP]; + GLint g = rgba[i][GCOMP] + specular[i][GCOMP]; + GLint b = rgba[i][BCOMP] + specular[i][BCOMP]; + rgba[i][RCOMP] = (GLchan) MIN2(r, CHAN_MAX); + rgba[i][GCOMP] = (GLchan) MIN2(g, CHAN_MAX); + rgba[i][BCOMP] = (GLchan) MIN2(b, CHAN_MAX); +#endif + } +} + + +/** + * XXX merge this code into the _swrast_write_rgba_span() routine! + * + * Draw to more than one RGBA color buffer (or none). + * All fragment operations, up to (but not) blending/logicop should + * have been done first. + */ +static void +multi_write_rgba_span( GLcontext *ctx, struct sw_span *span ) +{ +#if OLD_RENDERBUFFER + SWcontext *swrast = SWRAST_CONTEXT(ctx); +#endif + const GLuint colorMask = *((GLuint *) ctx->Color.ColorMask); + struct gl_framebuffer *fb = ctx->DrawBuffer; + const GLuint output = 0; + GLuint i; + + ASSERT(span->end < MAX_WIDTH); + ASSERT(colorMask != 0x0); + + for (i = 0; i < fb->_NumColorDrawBuffers[output]; i++) { + struct gl_renderbuffer *rb = fb->_ColorDrawBuffers[output][i]; + GLchan rgbaTmp[MAX_WIDTH][4]; + +#if OLD_RENDERBUFFER + /* obsolete code */ + GLuint bufferBit = fb->_ColorDrawBit[output][i]; + /* Set the current read/draw buffer */ + swrast->CurrentBufferBit = bufferBit; + if (swrast->Driver.SetBuffer) + (*swrast->Driver.SetBuffer)(ctx, ctx->DrawBuffer, bufferBit); +#endif + + /* make copy of incoming colors */ + MEMCPY( rgbaTmp, span->array->rgba, 4 * span->end * sizeof(GLchan) ); + + if (ctx->Color._LogicOpEnabled) { + _swrast_logicop_rgba_span(ctx, rb, span, rgbaTmp); + } + else if (ctx->Color.BlendEnabled) { + _swrast_blend_span(ctx, rb, span, rgbaTmp); + } + + if (colorMask != 0xffffffff) { + _swrast_mask_rgba_span(ctx, rb, span, rgbaTmp); + } + + if (span->arrayMask & SPAN_XY) { + /* array of pixel coords */ + ASSERT(rb->PutValues); + rb->PutValues(ctx, rb, span->end, span->array->x, + span->array->y, rgbaTmp, span->array->mask); + } + else { + /* horizontal run of pixels */ + ASSERT(rb->PutRow); + rb->PutRow(ctx, rb, span->end, span->x, span->y, rgbaTmp, + span->array->mask); + } + } + +#if OLD_RENDERBUFFER + /* restore default dest buffer */ + _swrast_use_draw_buffer(ctx); +#endif +} + + +/** + * Apply all the per-fragment operations to a span. + * This now includes texturing (_swrast_write_texture_span() is history). + * This function may modify any of the array values in the span. + * span->interpMask and span->arrayMask may be changed but will be restored + * to their original values before returning. + */ +void +_swrast_write_rgba_span( GLcontext *ctx, struct sw_span *span) +{ + const GLuint colorMask = *((GLuint *) ctx->Color.ColorMask); + SWcontext *swrast = SWRAST_CONTEXT(ctx); + const GLuint origInterpMask = span->interpMask; + const GLuint origArrayMask = span->arrayMask; + const GLboolean deferredTexture = !(ctx->Color.AlphaEnabled || + ctx->FragmentProgram._Active || + ctx->ATIFragmentShader._Enabled); + + ASSERT(span->primitive == GL_POINT || span->primitive == GL_LINE || + span->primitive == GL_POLYGON || span->primitive == GL_BITMAP); + ASSERT(span->end <= MAX_WIDTH); + ASSERT((span->interpMask & span->arrayMask) == 0); + + /* + printf("%s() interp 0x%x array 0x%x\n", __FUNCTION__, + span->interpMask, span->arrayMask); + */ + + if (span->arrayMask & SPAN_MASK) { + /* mask was initialized by caller, probably glBitmap */ + span->writeAll = GL_FALSE; + } + else { + _mesa_memset(span->array->mask, 1, span->end); + span->writeAll = GL_TRUE; + } + + /* Clip to window/scissor box */ + if ((swrast->_RasterMask & CLIP_BIT) || (span->primitive != GL_POLYGON)) { + if (!clip_span(ctx, span)) { + return; + } + } + +#ifdef DEBUG + /* Make sure all fragments are within window bounds */ + if (span->arrayMask & SPAN_XY) { + GLuint i; + for (i = 0; i < span->end; i++) { + if (span->array->mask[i]) { + assert(span->array->x[i] >= ctx->DrawBuffer->_Xmin); + assert(span->array->x[i] < ctx->DrawBuffer->_Xmax); + assert(span->array->y[i] >= ctx->DrawBuffer->_Ymin); + assert(span->array->y[i] < ctx->DrawBuffer->_Ymax); + } + } + } +#endif + + /* Polygon Stippling */ + if (ctx->Polygon.StippleFlag && span->primitive == GL_POLYGON) { + stipple_polygon_span(ctx, span); + } + + /* Interpolate texcoords? */ + if (ctx->Texture._EnabledCoordUnits + && (span->interpMask & SPAN_TEXTURE) + && (span->arrayMask & SPAN_TEXTURE) == 0) { + interpolate_texcoords(ctx, span); + } + + /* This is the normal place to compute the resulting fragment color/Z. + * As an optimization, we try to defer this until after Z/stencil + * testing in order to try to avoid computing colors that we won't + * actually need. + */ + if (!deferredTexture) { + /* Now we need the rgba array, fill it in if needed */ + if ((span->interpMask & SPAN_RGBA) && (span->arrayMask & SPAN_RGBA) == 0) + interpolate_colors(ctx, span); + + if (span->interpMask & SPAN_SPEC) + interpolate_specular(ctx, span); + + if (span->interpMask & SPAN_FOG) + interpolate_fog(ctx, span); + + /* Compute fragment colors with fragment program or texture lookups */ + if (ctx->FragmentProgram._Active) { + /* frag prog may need Z values */ + if (span->interpMask & SPAN_Z) + _swrast_span_interpolate_z(ctx, span); + _swrast_exec_fragment_program( ctx, span ); + } + else if (ctx->ATIFragmentShader._Enabled) + _swrast_exec_fragment_shader( ctx, span ); + else if (ctx->Texture._EnabledUnits && (span->arrayMask & SPAN_TEXTURE)) + _swrast_texture_span( ctx, span ); + + /* Do the alpha test */ + if (!_swrast_alpha_test(ctx, span)) { + span->arrayMask = origArrayMask; + return; + } + } + + /* Stencil and Z testing */ + if (ctx->Stencil.Enabled || ctx->Depth.Test) { + if (span->interpMask & SPAN_Z) + _swrast_span_interpolate_z(ctx, span); + + if (ctx->Stencil.Enabled && ctx->DrawBuffer->Visual.stencilBits > 0) { + /* Combined Z/stencil tests */ + if (!_swrast_stencil_and_ztest_span(ctx, span)) { + span->interpMask = origInterpMask; + span->arrayMask = origArrayMask; + return; + } + } + else if (ctx->DrawBuffer->Visual.depthBits > 0) { + /* Just regular depth testing */ + ASSERT(ctx->Depth.Test); + ASSERT(span->arrayMask & SPAN_Z); + if (!_swrast_depth_test_span(ctx, span)) { + span->interpMask = origInterpMask; + span->arrayMask = origArrayMask; + return; + } + } + } + + /* if we get here, some fragments passed the depth test */ + if (ctx->Depth.OcclusionTest) { + ctx->OcclusionResult = GL_TRUE; + } + +#if FEATURE_ARB_occlusion_query + if (ctx->Occlusion.Active) { + /* update count of 'passed' fragments */ + GLuint i; + for (i = 0; i < span->end; i++) + ctx->Occlusion.PassedCounter += span->array->mask[i]; + } +#endif + + /* We had to wait until now to check for glColorMask(0,0,0,0) because of + * the occlusion test. + */ + if (colorMask == 0x0) { + span->interpMask = origInterpMask; + span->arrayMask = origArrayMask; + return; + } + + /* If we were able to defer fragment color computation to now, there's + * a good chance that many fragments will have already been killed by + * Z/stencil testing. + */ + if (deferredTexture) { + /* Now we need the rgba array, fill it in if needed */ + if ((span->interpMask & SPAN_RGBA) && (span->arrayMask & SPAN_RGBA) == 0) + interpolate_colors(ctx, span); + + if (span->interpMask & SPAN_SPEC) + interpolate_specular(ctx, span); + + if (span->interpMask & SPAN_FOG) + interpolate_fog(ctx, span); + + if (ctx->FragmentProgram._Active) + _swrast_exec_fragment_program( ctx, span ); + else if (ctx->ATIFragmentShader._Enabled) + _swrast_exec_fragment_shader( ctx, span ); + else if (ctx->Texture._EnabledUnits && (span->arrayMask & SPAN_TEXTURE)) + _swrast_texture_span( ctx, span ); + } + + ASSERT(span->arrayMask & SPAN_RGBA); + + if (!ctx->FragmentProgram._Enabled) { + /* Add base and specular colors */ + if (ctx->Fog.ColorSumEnabled || + (ctx->Light.Enabled && + ctx->Light.Model.ColorControl == GL_SEPARATE_SPECULAR_COLOR)) { + if (span->interpMask & SPAN_SPEC) { + interpolate_specular(ctx, span); + } + if (span->arrayMask & SPAN_SPEC) { + add_colors( span->end, span->array->rgba, span->array->spec ); + } + else { + /* We probably added the base/specular colors during the + * vertex stage! + */ + } + } + } + + /* Fog */ + if (swrast->_FogEnabled) { + _swrast_fog_rgba_span(ctx, span); + } + + /* Antialias coverage application */ + if (span->arrayMask & SPAN_COVERAGE) { + GLchan (*rgba)[4] = span->array->rgba; + GLfloat *coverage = span->array->coverage; + GLuint i; + for (i = 0; i < span->end; i++) { + rgba[i][ACOMP] = (GLchan) (rgba[i][ACOMP] * coverage[i]); + } + } + + if (swrast->_RasterMask & MULTI_DRAW_BIT) { + /* need to do blend/logicop separately for each color buffer */ + multi_write_rgba_span(ctx, span); + } + else { + /* normal: write to exactly one buffer */ + struct gl_renderbuffer *rb = ctx->DrawBuffer->_ColorDrawBuffers[0][0]; + + if (ctx->Color._LogicOpEnabled) { + _swrast_logicop_rgba_span(ctx, rb, span, span->array->rgba); + } + else if (ctx->Color.BlendEnabled) { + _swrast_blend_span(ctx, rb, span, span->array->rgba); + } + + /* Color component masking */ + if (colorMask != 0xffffffff) { + _swrast_mask_rgba_span(ctx, rb, span, span->array->rgba); + } + + /* Finally, write the pixels to a color buffer */ + if (span->arrayMask & SPAN_XY) { + /* array of pixel coords */ + ASSERT(rb->PutValues); + ASSERT(rb->_BaseFormat == GL_RGB || rb->_BaseFormat == GL_RGBA); + /* XXX check datatype */ + rb->PutValues(ctx, rb, span->end, span->array->x, span->array->y, + span->array->rgba, span->array->mask); + } + else { + /* horizontal run of pixels */ + ASSERT(rb->PutRow); + ASSERT(rb->_BaseFormat == GL_RGB || rb->_BaseFormat == GL_RGBA); + /* XXX check datatype */ + rb->PutRow(ctx, rb, span->end, span->x, span->y, span->array->rgba, + span->writeAll ? NULL : span->array->mask); + } + } + + span->interpMask = origInterpMask; + span->arrayMask = origArrayMask; +} + + + +/** + * Read RGBA pixels from frame buffer. Clipping will be done to prevent + * reading ouside the buffer's boundaries. + */ +void +_swrast_read_rgba_span( GLcontext *ctx, struct gl_renderbuffer *rb, + GLuint n, GLint x, GLint y, GLchan rgba[][4] ) +{ + const GLint bufWidth = (GLint) rb->Width; + const GLint bufHeight = (GLint) rb->Height; + + if (y < 0 || y >= bufHeight || x + (GLint) n < 0 || x >= bufWidth) { + /* completely above, below, or right */ + /* XXX maybe leave rgba values undefined? */ + _mesa_bzero(rgba, 4 * n * sizeof(GLchan)); + } + else { + GLint skip, length; + if (x < 0) { + /* left edge clipping */ + skip = -x; + length = (GLint) n - skip; + if (length < 0) { + /* completely left of window */ + return; + } + if (length > bufWidth) { + length = bufWidth; + } + } + else if ((GLint) (x + n) > bufWidth) { + /* right edge clipping */ + skip = 0; + length = bufWidth - x; + if (length < 0) { + /* completely to right of window */ + return; + } + } + else { + /* no clipping */ + skip = 0; + length = (GLint) n; + } + + ASSERT(rb); + ASSERT(rb->GetRow); + ASSERT(rb->_BaseFormat == GL_RGB || rb->_BaseFormat == GL_RGBA); + ASSERT(rb->DataType == GL_UNSIGNED_BYTE); + rb->GetRow(ctx, rb, length, x + skip, y, rgba + skip); + } +} + + +/** + * Read CI pixels from frame buffer. Clipping will be done to prevent + * reading ouside the buffer's boundaries. + */ +void +_swrast_read_index_span( GLcontext *ctx, struct gl_renderbuffer *rb, + GLuint n, GLint x, GLint y, GLuint index[] ) +{ + const GLint bufWidth = (GLint) rb->Width; + const GLint bufHeight = (GLint) rb->Height; + + if (y < 0 || y >= bufHeight || x + (GLint) n < 0 || x >= bufWidth) { + /* completely above, below, or right */ + _mesa_bzero(index, n * sizeof(GLuint)); + } + else { + GLint skip, length; + if (x < 0) { + /* left edge clipping */ + skip = -x; + length = (GLint) n - skip; + if (length < 0) { + /* completely left of window */ + return; + } + if (length > bufWidth) { + length = bufWidth; + } + } + else if ((GLint) (x + n) > bufWidth) { + /* right edge clipping */ + skip = 0; + length = bufWidth - x; + if (length < 0) { + /* completely to right of window */ + return; + } + } + else { + /* no clipping */ + skip = 0; + length = (GLint) n; + } + + ASSERT(rb->GetRow); + ASSERT(rb->_BaseFormat == GL_COLOR_INDEX); + + if (rb->DataType == GL_UNSIGNED_BYTE) { + GLubyte index8[MAX_WIDTH]; + GLint i; + rb->GetRow(ctx, rb, length, x + skip, y, index8); + for (i = 0; i < length; i++) + index[skip + i] = index8[i]; + } + else if (rb->DataType == GL_UNSIGNED_SHORT) { + GLushort index16[MAX_WIDTH]; + GLint i; + rb->GetRow(ctx, rb, length, x + skip, y, index16); + for (i = 0; i < length; i++) + index[skip + i] = index16[i]; + } + else if (rb->DataType == GL_UNSIGNED_INT) { + rb->GetRow(ctx, rb, length, x + skip, y, index + skip); + } + } +} + + +/** + * Wrapper for gl_renderbuffer::GetValues() which does clipping to avoid + * reading values outside the buffer bounds. + * We can use this for reading any format/type of renderbuffer. + * \param valueSize is the size in bytes of each value put into the + * values array. + */ +void +_swrast_get_values(GLcontext *ctx, struct gl_renderbuffer *rb, + GLuint count, const GLint x[], const GLint y[], + void *values, GLuint valueSize) +{ + GLuint i, inCount = 0, inStart = 0; + + for (i = 0; i < count; i++) { + if (x[i] >= 0 && y[i] >= 0 && x[i] < rb->Width && y[i] < rb->Height) { + /* inside */ + if (inCount == 0) + inStart = i; + inCount++; + } + else { + if (inCount > 0) { + /* read [inStart, inStart + inCount) */ + rb->GetValues(ctx, rb, inCount, x + inStart, y + inStart, + (GLubyte *) values + inStart * valueSize); + inCount = 0; + } + } + } + if (inCount > 0) { + /* read last values */ + rb->GetValues(ctx, rb, inCount, x + inStart, y + inStart, + (GLubyte *) values + inStart * valueSize); + } +} |