diff options
| -rw-r--r-- | src/mesa/main/texstore.c | 71 | ||||
| -rw-r--r-- | src/mesa/main/texstore.h | 7 |
2 files changed, 78 insertions, 0 deletions
diff --git a/src/mesa/main/texstore.c b/src/mesa/main/texstore.c index d0529b13c3e..3dae1929c4d 100644 --- a/src/mesa/main/texstore.c +++ b/src/mesa/main/texstore.c @@ -3209,3 +3209,74 @@ _mesa_generate_mipmap(GLcontext *ctx, GLenum target, } /* loop over mipmap levels */ } + + +/** + * Helper function for drivers which need to rescale texture images to + * certain aspect ratios. + * Nearest filtering only (for broken hardware that can't support + * all aspect ratios). This can be made a lot faster, but I don't + * really care enough... + */ +void _mesa_rescale_teximage2d( GLuint bytesPerPixel, GLuint dstRowStride, + GLint srcWidth, GLint srcHeight, + GLint dstWidth, GLint dstHeight, + const GLvoid *srcImage, GLvoid *dstImage ) +{ + GLint row, col; + +#define INNER_LOOP( TYPE, HOP, WOP ) \ + for ( row = 0 ; row < dstHeight ; row++ ) { \ + GLint srcRow = row HOP hScale; \ + for ( col = 0 ; col < dstWidth ; col++ ) { \ + GLint srcCol = col WOP wScale; \ + dst[col] = src[srcRow * srcWidth + srcCol]; \ + } \ + dst = (TYPE *) ((GLubyte *) dst + dstRowStride); \ + } \ + +#define RESCALE_IMAGE( TYPE ) \ +do { \ + const TYPE *src = (const TYPE *)srcImage; \ + TYPE *dst = (TYPE *)dstImage; \ + \ + if ( srcHeight <= dstHeight ) { \ + const GLint hScale = dstHeight / srcHeight; \ + if ( srcWidth <= dstWidth ) { \ + const GLint wScale = dstWidth / srcWidth; \ + INNER_LOOP( TYPE, /, / ); \ + } \ + else { \ + const GLint wScale = srcWidth / dstWidth; \ + INNER_LOOP( TYPE, /, * ); \ + } \ + } \ + else { \ + const GLint hScale = srcHeight / dstHeight; \ + if ( srcWidth <= dstWidth ) { \ + const GLint wScale = dstWidth / srcWidth; \ + INNER_LOOP( TYPE, *, / ); \ + } \ + else { \ + const GLint wScale = srcWidth / dstWidth; \ + INNER_LOOP( TYPE, *, * ); \ + } \ + } \ +} while (0) + + switch ( bytesPerPixel ) { + case 4: + RESCALE_IMAGE( GLuint ); + break; + + case 2: + RESCALE_IMAGE( GLushort ); + break; + + case 1: + RESCALE_IMAGE( GLubyte ); + break; + default: + _mesa_problem(NULL,"unexpected bytes/pixel in _mesa_rescale_teximage2d"); + } +} diff --git a/src/mesa/main/texstore.h b/src/mesa/main/texstore.h index 47775a1bb81..d276ff94e47 100644 --- a/src/mesa/main/texstore.h +++ b/src/mesa/main/texstore.h @@ -225,4 +225,11 @@ _mesa_generate_mipmap(GLcontext *ctx, GLenum target, const struct gl_texture_unit *texUnit, struct gl_texture_object *texObj); + +extern void +_mesa_rescale_teximage2d(GLuint bytesPerPixel, GLuint dstRowStride, + GLint srcWidth, GLint srcHeight, + GLint dstWidth, GLint dstHeight, + const GLvoid *srcImage, GLvoid *dstImage); + #endif |