From 727b2d747e13fed78bf62cfbf4a31427eed0ef29 Mon Sep 17 00:00:00 2001 From: Brian Paul Date: Wed, 5 Aug 2009 13:21:59 -0600 Subject: mesa: make _mesa_clip_blit() a shared function --- src/mesa/main/image.c | 178 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 178 insertions(+) (limited to 'src/mesa/main/image.c') diff --git a/src/mesa/main/image.c b/src/mesa/main/image.c index 01fbe40a03..1a4d22256f 100644 --- a/src/mesa/main/image.c +++ b/src/mesa/main/image.c @@ -5333,3 +5333,181 @@ _mesa_clip_to_region(GLint xmin, GLint ymin, return GL_TRUE; } + + +/** + * Clip dst coords against Xmax (or Ymax). + */ +static INLINE void +clip_right_or_top(GLint *srcX0, GLint *srcX1, + GLint *dstX0, GLint *dstX1, + GLint maxValue) +{ + GLfloat t, bias; + + if (*dstX1 > maxValue) { + /* X1 outside right edge */ + ASSERT(*dstX0 < maxValue); /* X0 should be inside right edge */ + t = (GLfloat) (maxValue - *dstX0) / (GLfloat) (*dstX1 - *dstX0); + /* chop off [t, 1] part */ + ASSERT(t >= 0.0 && t <= 1.0); + *dstX1 = maxValue; + bias = (*srcX0 < *srcX1) ? 0.5 : -0.5; + *srcX1 = *srcX0 + (GLint) (t * (*srcX1 - *srcX0) + bias); + } + else if (*dstX0 > maxValue) { + /* X0 outside right edge */ + ASSERT(*dstX1 < maxValue); /* X1 should be inside right edge */ + t = (GLfloat) (maxValue - *dstX1) / (GLfloat) (*dstX0 - *dstX1); + /* chop off [t, 1] part */ + ASSERT(t >= 0.0 && t <= 1.0); + *dstX0 = maxValue; + bias = (*srcX0 < *srcX1) ? -0.5 : 0.5; + *srcX0 = *srcX1 + (GLint) (t * (*srcX0 - *srcX1) + bias); + } +} + + +/** + * Clip dst coords against Xmin (or Ymin). + */ +static INLINE void +clip_left_or_bottom(GLint *srcX0, GLint *srcX1, + GLint *dstX0, GLint *dstX1, + GLint minValue) +{ + GLfloat t, bias; + + if (*dstX0 < minValue) { + /* X0 outside left edge */ + ASSERT(*dstX1 > minValue); /* X1 should be inside left edge */ + t = (GLfloat) (minValue - *dstX0) / (GLfloat) (*dstX1 - *dstX0); + /* chop off [0, t] part */ + ASSERT(t >= 0.0 && t <= 1.0); + *dstX0 = minValue; + bias = (*srcX0 < *srcX1) ? 0.5 : -0.5; /* flipped??? */ + *srcX0 = *srcX0 + (GLint) (t * (*srcX1 - *srcX0) + bias); + } + else if (*dstX1 < minValue) { + /* X1 outside left edge */ + ASSERT(*dstX0 > minValue); /* X0 should be inside left edge */ + t = (GLfloat) (minValue - *dstX1) / (GLfloat) (*dstX0 - *dstX1); + /* chop off [0, t] part */ + ASSERT(t >= 0.0 && t <= 1.0); + *dstX1 = minValue; + bias = (*srcX0 < *srcX1) ? 0.5 : -0.5; + *srcX1 = *srcX1 + (GLint) (t * (*srcX0 - *srcX1) + bias); + } +} + + +/** + * Do clipping of blit src/dest rectangles. + * The dest rect is clipped against both the buffer bounds and scissor bounds. + * The src rect is just clipped against the buffer bounds. + * + * When either the src or dest rect is clipped, the other is also clipped + * proportionately! + * + * Note that X0 need not be less than X1 (same for Y) for either the source + * and dest rects. That makes the clipping a little trickier. + * + * \return GL_TRUE if anything is left to draw, GL_FALSE if totally clipped + */ +GLboolean +_mesa_clip_blit(GLcontext *ctx, + GLint *srcX0, GLint *srcY0, GLint *srcX1, GLint *srcY1, + GLint *dstX0, GLint *dstY0, GLint *dstX1, GLint *dstY1) +{ + const GLint srcXmin = 0; + const GLint srcXmax = ctx->ReadBuffer->Width; + const GLint srcYmin = 0; + const GLint srcYmax = ctx->ReadBuffer->Height; + + /* these include scissor bounds */ + const GLint dstXmin = ctx->DrawBuffer->_Xmin; + const GLint dstXmax = ctx->DrawBuffer->_Xmax; + const GLint dstYmin = ctx->DrawBuffer->_Ymin; + const GLint dstYmax = ctx->DrawBuffer->_Ymax; + + /* + printf("PreClipX: src: %d .. %d dst: %d .. %d\n", + *srcX0, *srcX1, *dstX0, *dstX1); + printf("PreClipY: src: %d .. %d dst: %d .. %d\n", + *srcY0, *srcY1, *dstY0, *dstY1); + */ + + /* trivial rejection tests */ + if (*dstX0 == *dstX1) + return GL_FALSE; /* no width */ + if (*dstX0 <= dstXmin && *dstX1 <= dstXmin) + return GL_FALSE; /* totally out (left) of bounds */ + if (*dstX0 >= dstXmax && *dstX1 >= dstXmax) + return GL_FALSE; /* totally out (right) of bounds */ + + if (*dstY0 == *dstY1) + return GL_FALSE; + if (*dstY0 <= dstYmin && *dstY1 <= dstYmin) + return GL_FALSE; + if (*dstY0 >= dstYmax && *dstY1 >= dstYmax) + return GL_FALSE; + + if (*srcX0 == *srcX1) + return GL_FALSE; + if (*srcX0 <= srcXmin && *srcX1 <= srcXmin) + return GL_FALSE; + if (*srcX0 >= srcXmax && *srcX1 >= srcXmax) + return GL_FALSE; + + if (*srcY0 == *srcY1) + return GL_FALSE; + if (*srcY0 <= srcYmin && *srcY1 <= srcYmin) + return GL_FALSE; + if (*srcY0 >= srcYmax && *srcY1 >= srcYmax) + return GL_FALSE; + + /* + * dest clip + */ + clip_right_or_top(srcX0, srcX1, dstX0, dstX1, dstXmax); + clip_right_or_top(srcY0, srcY1, dstY0, dstY1, dstYmax); + clip_left_or_bottom(srcX0, srcX1, dstX0, dstX1, dstXmin); + clip_left_or_bottom(srcY0, srcY1, dstY0, dstY1, dstYmin); + + /* + * src clip (just swap src/dst values from above) + */ + clip_right_or_top(dstX0, dstX1, srcX0, srcX1, srcXmax); + clip_right_or_top(dstY0, dstY1, srcY0, srcY1, srcYmax); + clip_left_or_bottom(dstX0, dstX1, srcX0, srcX1, srcXmin); + clip_left_or_bottom(dstY0, dstY1, srcY0, srcY1, srcYmin); + + /* + printf("PostClipX: src: %d .. %d dst: %d .. %d\n", + *srcX0, *srcX1, *dstX0, *dstX1); + printf("PostClipY: src: %d .. %d dst: %d .. %d\n", + *srcY0, *srcY1, *dstY0, *dstY1); + */ + + ASSERT(*dstX0 >= dstXmin); + ASSERT(*dstX0 <= dstXmax); + ASSERT(*dstX1 >= dstXmin); + ASSERT(*dstX1 <= dstXmax); + + ASSERT(*dstY0 >= dstYmin); + ASSERT(*dstY0 <= dstYmax); + ASSERT(*dstY1 >= dstYmin); + ASSERT(*dstY1 <= dstYmax); + + ASSERT(*srcX0 >= srcXmin); + ASSERT(*srcX0 <= srcXmax); + ASSERT(*srcX1 >= srcXmin); + ASSERT(*srcX1 <= srcXmax); + + ASSERT(*srcY0 >= srcYmin); + ASSERT(*srcY0 <= srcYmax); + ASSERT(*srcY1 >= srcYmin); + ASSERT(*srcY1 <= srcYmax); + + return GL_TRUE; +} -- cgit v1.2.3