-/* $Id: s_span.c,v 1.21 2002/01/10 16:54:29 brianp Exp $ */
+/* $Id: s_span.c,v 1.22 2002/01/16 16:00:03 brianp Exp $ */
/*
* Mesa 3-D graphics library
}
+/*
+ * Write a horizontal span of textured pixels to the frame buffer.
+ * The color of each pixel is different.
+ * Alpha-testing, stenciling, depth-testing, and blending are done
+ * as needed.
+ * Input: span - contains span-data with the exception of
+ * fog - array of fog factor values in [0,1]
+ * primitive - either GL_POINT, GL_LINE, GL_POLYGON or GL_BITMAP.
+ */
+void
+_mesa_write_texture_span( GLcontext *ctx, struct sw_span *span,
+ const GLfloat fog[], GLenum primitive )
+{
+ const GLuint colorMask = *((GLuint *) ctx->Color.ColorMask);
+ GLchan rgbaBackup[MAX_WIDTH][4];
+ GLchan (*rgba)[4]; /* points to either rgbaIn or rgbaBackup */
+ SWcontext *swrast = SWRAST_CONTEXT(ctx);
+
+ SET_MASK_TO_ONE(span);
+
+ if ((swrast->_RasterMask & WINCLIP_BIT) || primitive==GL_BITMAP) {
+ if (clip_span(ctx,span) == GL_FALSE) {
+ return;
+ }
+ }
+
+ /* Do the scissor test */
+ if (ctx->Scissor.Enabled) {
+ if (_mesa_scissor_span( ctx, span ) == GL_FALSE) {
+ return;
+ }
+ }
+
+ /* Polygon Stippling */
+ if (ctx->Polygon.StippleFlag && primitive==GL_POLYGON) {
+ stipple_polygon_span( ctx, span);
+ }
+
+
+ if (primitive==GL_BITMAP || (swrast->_RasterMask & MULTI_DRAW_BIT)) {
+ /* must make a copy of the colors since they may be modified */
+ MEMCPY(rgbaBackup, span->color.rgba, 4 * span->end * sizeof(GLchan));
+ rgba = rgbaBackup;
+ }
+ else {
+ rgba = span->color.rgba;
+ }
+
+
+ /* Texture with alpha test */
+ if (ctx->Color.AlphaEnabled) {
+ /* Texturing without alpha is done after depth-testing which
+ gives a potential speed-up. */
+ ASSERT(ctx->Texture._ReallyEnabled);
+ _swrast_texture_fragments( ctx, 0, span, rgba );
+
+ /* Do the alpha test */
+ if (_mesa_alpha_test( ctx, span->end, (const GLchan (*)[4]) rgba, span->mask ) == 0) {
+ return;
+ }
+ span->write_all = GL_FALSE;
+ }
+
+ if (ctx->Stencil.Enabled) {
+ /* first stencil test */
+ if (_mesa_stencil_and_ztest_span(ctx, span) == GL_FALSE)
+ return;
+ }
+ else if (ctx->Depth.Test) {
+ /* regular depth testing */
+ if (_mesa_depth_test_span(ctx, span) == 0)
+ return;
+ }
+
+ /* if we get here, something passed the depth test */
+ ctx->OcclusionResult = GL_TRUE;
+
+ /* Texture without alpha test */
+ if (! ctx->Color.AlphaEnabled) {
+ ASSERT(ctx->Texture._ReallyEnabled);
+ _swrast_texture_fragments( ctx, 0, span, rgba );
+ }
+
+
+ /* Add base and specular colors */
+ if ((span->activeMask & SPAN_SPEC) && /* Is this right test ???*/
+ (ctx->Fog.ColorSumEnabled ||
+ (ctx->Light.Enabled &&
+ ctx->Light.Model.ColorControl == GL_SEPARATE_SPECULAR_COLOR)))
+ add_colors(span, rgba); /* rgba = rgba + spec */
+
+ /* Per-pixel fog */
+ if (ctx->Fog.Enabled) {
+ /* Is this the right 'if' ?? */
+ if ((span->activeMask & SPAN_FOG) && !swrast->_PreferPixelFog)
+ _old_fog_rgba_pixels( ctx, span->end, fog, rgba );
+ else
+ _mesa_depth_fog_rgba_pixels(ctx, span, rgba);
+ }
+
+
+ /* Antialias coverage application */
+#if 0
+ if (span->coverage) {
+ GLuint i;
+ for (i = 0; i < span->end; i++) {
+ rgba[i][ACOMP] = (GLchan) (rgba[i][ACOMP] * span->coverage[i]);
+ }
+ }
+#endif
+
+ if (swrast->_RasterMask & MULTI_DRAW_BIT) {
+ multi_write_rgba_span( ctx, span->end, span->x, span->y, (const GLchan (*)[4]) rgba, span->mask );
+ }
+ else {
+ /* normal: write to exactly one buffer */
+ if (ctx->Color.ColorLogicOpEnabled) {
+ _mesa_logicop_rgba_span( ctx, span->end, span->x, span->y, rgba, span->mask );
+ }
+ else if (ctx->Color.BlendEnabled) {
+ _mesa_blend_span( ctx, span->end, span->x, span->y, rgba, span->mask );
+ }
+ if (colorMask == 0x0) {
+ return;
+ }
+ else if (colorMask != 0xffffffff) {
+ _mesa_mask_rgba_span( ctx, span->end, span->x, span->y, rgba );
+ }
+
+ (*swrast->Driver.WriteRGBASpan)( ctx, span->end, span->x, span->y, (const GLchan (*)[4])rgba,
+ span->write_all ? NULL : span->mask );
+ if (swrast->_RasterMask & ALPHABUF_BIT) {
+ _mesa_write_alpha_span( ctx, span->end, span->x, span->y, (const GLchan (*)[4]) rgba,
+ span->write_all ? NULL : span->mask );
+ }
+ }
+
+}
+
+
/*
* Write a horizontal span of textured pixels to the frame buffer.
* The color of each pixel is different.