From 547a418888c455a3f5158c147a155292f398ea34 Mon Sep 17 00:00:00 2001 From: Brian Paul Date: Mon, 21 Jan 2013 08:59:25 -0700 Subject: swrast: fix blit code's nearest/linear coordinate arithmetic MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Fixes piglit's fbo-blit-stretch test. Reviewed-by: José Fonseca --- src/mesa/swrast/s_blit.c | 23 ++++++++--------------- 1 file changed, 8 insertions(+), 15 deletions(-) (limited to 'src/mesa/swrast') diff --git a/src/mesa/swrast/s_blit.c b/src/mesa/swrast/s_blit.c index 08ec5e2d0e0..82fa43f1c73 100644 --- a/src/mesa/swrast/s_blit.c +++ b/src/mesa/swrast/s_blit.c @@ -304,7 +304,8 @@ blit_nearest(struct gl_context *ctx, } for (dstRow = 0; dstRow < dstHeight; dstRow++) { - GLint srcRow = (dstRow * srcHeight) / dstHeight; + GLfloat srcRowF = (dstRow + 0.5F) / dstHeight * srcHeight - 0.5F; + GLint srcRow = IROUND(srcRowF); GLubyte *dstRowStart = dstMap + dstRowStride * dstRow; ASSERT(srcRow >= 0); @@ -404,17 +405,15 @@ resample_linear_row_ub(GLint srcWidth, GLint dstWidth, const GLubyte (*srcColor0)[4] = (const GLubyte (*)[4]) srcBuffer0; const GLubyte (*srcColor1)[4] = (const GLubyte (*)[4]) srcBuffer1; GLubyte (*dstColor)[4] = (GLubyte (*)[4]) dstBuffer; - const GLfloat dstWidthF = (GLfloat) dstWidth; GLint dstCol; for (dstCol = 0; dstCol < dstWidth; dstCol++) { - const GLfloat srcCol = (dstCol * srcWidth) / dstWidthF; - GLint srcCol0 = IFLOOR(srcCol); + const GLfloat srcCol = (dstCol + 0.5F) / dstWidth * srcWidth - 0.5F; + GLint srcCol0 = MAX2(0, IFLOOR(srcCol)); GLint srcCol1 = srcCol0 + 1; GLfloat colWeight = srcCol - srcCol0; /* fractional part of srcCol */ GLfloat red, green, blue, alpha; - ASSERT(srcCol0 >= 0); ASSERT(srcCol0 < srcWidth); ASSERT(srcCol1 <= srcWidth); @@ -461,17 +460,15 @@ resample_linear_row_float(GLint srcWidth, GLint dstWidth, const GLfloat (*srcColor0)[4] = (const GLfloat (*)[4]) srcBuffer0; const GLfloat (*srcColor1)[4] = (const GLfloat (*)[4]) srcBuffer1; GLfloat (*dstColor)[4] = (GLfloat (*)[4]) dstBuffer; - const GLfloat dstWidthF = (GLfloat) dstWidth; GLint dstCol; for (dstCol = 0; dstCol < dstWidth; dstCol++) { - const GLfloat srcCol = (dstCol * srcWidth) / dstWidthF; - GLint srcCol0 = IFLOOR(srcCol); + const GLfloat srcCol = (dstCol + 0.5F) / dstWidth * srcWidth - 0.5F; + GLint srcCol0 = MAX2(0, IFLOOR(srcCol)); GLint srcCol1 = srcCol0 + 1; GLfloat colWeight = srcCol - srcCol0; /* fractional part of srcCol */ GLfloat red, green, blue, alpha; - ASSERT(srcCol0 >= 0); ASSERT(srcCol0 < srcWidth); ASSERT(srcCol1 <= srcWidth); @@ -526,7 +523,6 @@ blit_linear(struct gl_context *ctx, const GLint dstWidth = ABS(dstX1 - dstX0); const GLint srcHeight = ABS(srcY1 - srcY0); const GLint dstHeight = ABS(dstY1 - dstY0); - const GLfloat dstHeightF = (GLfloat) dstHeight; const GLint srcXpos = MIN2(srcX0, srcX1); const GLint srcYpos = MIN2(srcY0, srcY1); @@ -654,14 +650,11 @@ blit_linear(struct gl_context *ctx, for (dstRow = 0; dstRow < dstHeight; dstRow++) { const GLint dstY = dstYpos + dstRow; - const GLfloat srcRow = (dstRow * srcHeight) / dstHeightF; - GLint srcRow0 = IFLOOR(srcRow); + GLfloat srcRow = (dstRow + 0.5F) / dstHeight * srcHeight - 0.5F; + GLint srcRow0 = MAX2(0, IFLOOR(srcRow)); GLint srcRow1 = srcRow0 + 1; GLfloat rowWeight = srcRow - srcRow0; /* fractional part of srcRow */ - ASSERT(srcRow >= 0); - ASSERT(srcRow < srcHeight); - if (srcRow1 == srcHeight) { /* last row fudge */ srcRow1 = srcRow0; -- cgit v1.2.3