/* 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( GLint texelBytes,
GLint srcWidth, GLint srcHeight,
GLint dstWidth, GLint dstHeight,
const GLvoid *srcImage, GLvoid *dstImage )
{
GLint row, col;
#define INNER_LOOP( 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++ = src[srcRow * srcWidth + srcCol]; \
} \
} \
#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( /, / ); \
} \
else { \
const GLint wScale = srcWidth / dstWidth; \
INNER_LOOP( /, * ); \
} \
} \
else { \
const GLint hScale = srcHeight / dstHeight; \
if ( srcWidth <= dstWidth ) { \
const GLint wScale = dstWidth / srcWidth; \
INNER_LOOP( *, / ); \
} \
else { \
const GLint wScale = srcWidth / dstWidth; \
INNER_LOOP( *, * ); \
} \
} \
} while (0)
switch ( texelBytes ) {
case 4:
RESCALE_IMAGE( GLuint );
break;
case 2:
RESCALE_IMAGE( GLushort );
break;
case 1:
RESCALE_IMAGE( GLubyte );
break;
}
}
/* 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");
}
}
