diff --git a/src/external/rlsw.h b/src/external/rlsw.h index 7e153adbc..85e4e8740 100644 --- a/src/external/rlsw.h +++ b/src/external/rlsw.h @@ -5385,6 +5385,17 @@ static void SW_RASTER_TRIANGLE_SPAN(const sw_vertex_t *start, const sw_vertex_t int xEnd = (int)end->position[0]; if (xStart == xEnd) return; + // Intercept the span bounds to ensure we don't write before the framebuffer. + int xLoopStart = (xStart >= 0)? xStart : 0; + int xLoopEnd = (xEnd <= RLSW.colorBuffer->width)? xEnd : RLSW.colorBuffer->width; + // Nothing to draw. + if (xLoopStart >= xLoopEnd) return; + + // Get the current row and skip if outside the framebuffer. + // Maybe this check is better suited elsewhere? + int y = (int)start->position[1]; + if (y < 0 || y >= RLSW.colorBuffer->height) return; + // Compute the inverse horizontal distance along the X axis float dxRcp = sw_rcp(end->position[0] - start->position[0]); @@ -5405,27 +5416,29 @@ static void SW_RASTER_TRIANGLE_SPAN(const sw_vertex_t *start, const sw_vertex_t #endif // Compute the subpixel distance to traverse before the first pixel + // Also step further into them to move away from the colorbuffer edge. float xSubstep = 1.0f - sw_fract(start->position[0]); + float dxStart = (float)(xLoopStart - xStart); + float xOffset = xSubstep + dxStart; - // Initializing the interpolation starting values - float w = start->position[3] + dWdx*xSubstep; + // Initializing the interpolation starting values. + float w = start->position[3] + dWdx*xOffset; float color[4] = { - start->color[0] + dCdx[0]*xSubstep, - start->color[1] + dCdx[1]*xSubstep, - start->color[2] + dCdx[2]*xSubstep, - start->color[3] + dCdx[3]*xSubstep + start->color[0] + dCdx[0]*xOffset, + start->color[1] + dCdx[1]*xOffset, + start->color[2] + dCdx[2]*xOffset, + start->color[3] + dCdx[3]*xOffset }; #ifdef SW_ENABLE_DEPTH_TEST - float z = start->position[2] + dZdx*xSubstep; + float z = start->position[2] + dZdx*xOffset; #endif #ifdef SW_ENABLE_TEXTURE - float u = start->texcoord[0] + dUdx*xSubstep; - float v = start->texcoord[1] + dVdx*xSubstep; + float u = start->texcoord[0] + dUdx*xOffset; + float v = start->texcoord[1] + dVdx*xOffset; #endif // Pre-calculate the starting pointers for the framebuffer row - int y = (int)start->position[1]; - int baseOffset = y*RLSW.colorBuffer->width + xStart; + int baseOffset = y*RLSW.colorBuffer->width + xLoopStart; uint8_t *cPtr = (uint8_t *)(RLSW.colorBuffer->pixels) + baseOffset*SW_FRAMEBUFFER_COLOR_SIZE; #ifdef SW_ENABLE_DEPTH_TEST uint8_t *dPtr = (uint8_t *)(RLSW.depthBuffer->pixels) + baseOffset*SW_FRAMEBUFFER_DEPTH_SIZE; @@ -5433,12 +5446,12 @@ static void SW_RASTER_TRIANGLE_SPAN(const sw_vertex_t *start, const sw_vertex_t #define SW_AFFINE_BLOCK 16 - int x = xStart; - while (x < xEnd) + int x = xLoopStart; + while (x < xLoopEnd) { // Clamp last block to remaining pixels int blockEnd = x + SW_AFFINE_BLOCK; - if (blockEnd > xEnd) blockEnd = xEnd; + if (blockEnd > xLoopEnd) blockEnd = xLoopEnd; float blockLenF = (float)(blockEnd - x); float blockLenRcp = sw_rcp(blockLenF); @@ -5673,6 +5686,14 @@ static void SW_RASTER_QUAD(const sw_vertex_t *a, const sw_vertex_t *b, int xMax = (int)br->position[0]; int yMax = (int)br->position[1]; + // Exit early if no pixels to draw. Use these later for loop boundaries + int yLoopMin = (yMin >= 0)? yMin : 0; + int xLoopMin = (xMin >= 0)? xMin : 0; + int yLoopMax = (yMax <= RLSW.colorBuffer->height)? yMax : RLSW.colorBuffer->height; + int xLoopMax = (xMax <= RLSW.colorBuffer->width)? xMax : RLSW.colorBuffer->width; + + if (yLoopMin >= yLoopMax || xLoopMin >= xLoopMax) return; + float w = (float)(xMax - xMin); float h = (float)(yMax - yMin); if ((w <= 0) || (h <= 0)) return; @@ -5726,21 +5747,44 @@ static void SW_RASTER_QUAD(const sw_vertex_t *a, const sw_vertex_t *b, uint8_t *dPixels = RLSW.depthBuffer->pixels; #endif - for (int y = yMin; y < yMax; y++) + // Calculate the distance the in-bounds boundary is from the quad's edges, only on the left and top. + float dxMin = (float)(xLoopMin - xMin); + float dyMin = (float)(yLoopMin - yMin); + + // Correct our start by how far we clipped outside the framebuffer. + cRow[0] += dCdx[0]*dxMin + dCdy[0]*dyMin; + cRow[1] += dCdx[1]*dxMin + dCdy[1]*dyMin; + cRow[2] += dCdx[2]*dxMin + dCdy[2]*dyMin; + cRow[3] += dCdx[3]*dxMin + dCdy[3]*dyMin; + #ifdef SW_ENABLE_DEPTH_TEST + zRow += dZdy*dyMin + dZdx*dxMin; + #endif + #ifdef SW_ENABLE_TEXTURE + uRow += dUdy*dyMin + dUdx*dxMin; + vRow += dVdy*dyMin + dVdx*dxMin; + #endif + + for (int y = yLoopMin; y < yLoopMax; y++) { - int baseOffset = y*stride + xMin; + int baseOffset = y*stride + xLoopMin; uint8_t *cPtr = cPixels + baseOffset*SW_FRAMEBUFFER_COLOR_SIZE; #ifdef SW_ENABLE_DEPTH_TEST uint8_t *dPtr = dPixels + baseOffset*SW_FRAMEBUFFER_DEPTH_SIZE; + // Copy the cursors so we increment them ourselves without destroying the offset maths. float z = zRow; #endif #ifdef SW_ENABLE_TEXTURE float u = uRow; float v = vRow; #endif - float color[4] = { cRow[0], cRow[1], cRow[2], cRow[3] }; + float color[4] = { + cRow[0], + cRow[1], + cRow[2], + cRow[3] + }; - for (int x = xMin; x < xMax; x++) + for (int x = xLoopMin; x < xLoopMax; x++) { float srcColor[4] = { color[0], color[1], color[2], color[3] }; @@ -5779,6 +5823,7 @@ static void SW_RASTER_QUAD(const sw_vertex_t *a, const sw_vertex_t *b, #ifdef SW_ENABLE_DEPTH_TEST discard: #endif + // We move one pixel over without touching the original "start offset" color[0] += dCdx[0]; color[1] += dCdx[1]; color[2] += dCdx[2]; @@ -5801,6 +5846,9 @@ static void SW_RASTER_QUAD(const sw_vertex_t *a, const sw_vertex_t *b, cPtr += SW_FRAMEBUFFER_COLOR_SIZE; } + // The for loop is clamped to the right side of the screen. + // However, these cursor start vars are still on the left. + // That's fine. We just need to advance to the next row. cRow[0] += dCdy[0]; cRow[1] += dCdy[1]; cRow[2] += dCdy[2];