-/* $Id: texutil.c,v 1.1 2000/03/24 20:54:21 brianp Exp $ */
+/* $Id: texutil.c,v 1.2 2000/03/27 18:56:26 brianp Exp $ */
/*
* Mesa 3-D graphics library
#include "all.h"
#else
#include "glheader.h"
+#include "context.h"
#include "image.h"
#include "mem.h"
#include "texutil.h"
}
return GL_TRUE;
}
+
+
+/*
+ * Used to convert 16-bit texels into GLubyte color components.
+ */
+static GLubyte R5G6B5toRed[0xffff];
+static GLubyte R5G6B5toGreen[0xffff];
+static GLubyte R5G6B5toBlue[0xffff];
+
+static GLubyte A4R4G4B4toRed[0xffff];
+static GLubyte A4R4G4B4toGreen[0xffff];
+static GLubyte A4R4G4B4toBlue[0xffff];
+static GLubyte A4R4G4B4toAlpha[0xffff];
+
+static GLubyte A1R5G5B5toRed[0xffff];
+static GLubyte A1R5G5B5toGreen[0xffff];
+static GLubyte A1R5G5B5toBlue[0xffff];
+static GLubyte A1R5G5B5toAlpha[0xffff];
+
+static void
+generate_lookup_tables(void)
+{
+ GLint i;
+ for (i = 0; i <= 0xffff; i++) {
+ GLint r = (i >> 8) & 0xf8;
+ GLint g = (i >> 3) & 0xfc;
+ GLint b = (i << 3) & 0xf8;
+ r = r * 255 / 0xf8;
+ g = g * 255 / 0xfc;
+ b = b * 255 / 0xf8;
+ R5G6B5toRed[i] = r;
+ R5G6B5toGreen[i] = g;
+ R5G6B5toBlue[i] = b;
+ }
+
+ for (i = 0; i <= 0xffff; i++) {
+ GLint r = (i >> 8) & 0xf;
+ GLint g = (i >> 4) & 0xf;
+ GLint b = (i ) & 0xf;
+ GLint a = (i >> 12) & 0xf;
+ r = r * 255 / 0xf;
+ g = g * 255 / 0xf;
+ b = b * 255 / 0xf;
+ a = a * 255 / 0xf;
+ A4R4G4B4toRed[i] = r;
+ A4R4G4B4toGreen[i] = g;
+ A4R4G4B4toBlue[i] = b;
+ A4R4G4B4toAlpha[i] = b;
+ }
+
+ for (i = 0; i <= 0xffff; i++) {
+ GLint r = (i >> 10) & 0xf8;
+ GLint g = (i >> 5) & 0xf8;
+ GLint b = (i ) & 0xf8;
+ GLint a = (i >> 15) & 0x1;
+ r = r * 255 / 0xf8;
+ g = g * 255 / 0xf8;
+ b = b * 255 / 0xf8;
+ a = a * 255;
+ A1R5G5B5toRed[i] = r;
+ A1R5G5B5toGreen[i] = g;
+ A1R5G5B5toBlue[i] = b;
+ A1R5G5B5toAlpha[i] = b;
+ }
+}
+
+
+
+/*
+ * Convert a texture image from an internal format to one of Mesa's
+ * core internal formats. This is likely to be used by glGetTexImage
+ * and for fetching texture images when falling back to software rendering.
+ *
+ * Notes:
+ * This function will do power of two image down-scaling to accomodate
+ * drivers with limited texture image aspect ratios.
+ * The implicit dest data type is GL_UNSIGNED_BYTE.
+ */
+void
+_mesa_unconvert_teximage(MesaIntTexFormat srcFormat,
+ GLint srcWidth, GLint srcHeight,
+ const GLvoid *srcImage,
+ GLsizei dstWidth, GLsizei dstHeight,
+ GLenum dstFormat, GLubyte *dstImage)
+{
+ static GLboolean firstCall = GL_TRUE;
+ const GLint wScale = srcWidth / dstWidth; /* must be power of two */
+ const GLint hScale = srcHeight / dstHeight; /* must be power of two */
+ ASSERT(srcWidth >= dstWidth);
+ ASSERT(srcHeight >= dstHeight);
+ ASSERT(dstImage);
+ ASSERT(srcImage);
+
+ if (firstCall) {
+ generate_lookup_tables();
+ firstCall = GL_FALSE;
+ }
+
+ switch (srcFormat) {
+ case MESA_I8:
+ case MESA_L8:
+ case MESA_A8:
+ case MESA_C8:
+#ifdef DEBUG
+ if (srcFormat == MESA_I8) {
+ ASSERT(dstFormat == GL_INTENSITY);
+ }
+ else if (srcFormat == MESA_L8) {
+ ASSERT(dstFormat == GL_LUMINANCE);
+ }
+ else if (srcFormat == MESA_A8) {
+ ASSERT(dstFormat == GL_ALPHA);
+ }
+ else if (srcFormat == MESA_C8) {
+ ASSERT(dstFormat == GL_COLOR_INDEX);
+ }
+#endif
+ if (wScale == 1 && hScale == 1) {
+ /* easy! */
+ MEMCPY(dstImage, srcImage, dstWidth * dstHeight * sizeof(GLubyte));
+ }
+ else {
+ /* rescale */
+ const GLubyte *src8 = (const GLubyte *) srcImage;
+ GLint row, col;
+ for (row = 0; row < dstHeight; row++) {
+ GLint srcRow = row * hScale;
+ for (col = 0; col < dstWidth; col++) {
+ GLint srcCol = col * wScale;
+ *dstImage++ = src8[srcRow * srcWidth + srcCol];
+ }
+ }
+ }
+ break;
+ case MESA_L8_A8:
+ ASSERT(dstFormat == GL_LUMINANCE_ALPHA);
+ if (wScale == 1 && hScale == 1) {
+ GLint i, n = dstWidth * dstHeight;
+ const GLushort *texel = (const GLushort *) srcImage;
+ for (i = 0; i < n; i++) {
+ const GLushort tex = *texel++;
+ *dstImage++ = (tex >> 8); /* luminance */
+ *dstImage++ = (tex & 0xff); /* alpha */
+ }
+ }
+ else {
+ /* rescale */
+ const GLushort *src16 = (const GLushort *) srcImage;
+ GLint row, col;
+ for (row = 0; row < dstHeight; row++) {
+ GLint srcRow = row * hScale;
+ for (col = 0; col < dstWidth; col++) {
+ GLint srcCol = col * wScale;
+ const GLushort tex = src16[srcRow * srcWidth + srcCol];
+ *dstImage++ = (tex >> 8); /* luminance */
+ *dstImage++ = (tex & 0xff); /* alpha */
+ }
+ }
+ }
+ break;
+ case MESA_R5_G6_B5:
+ ASSERT(dstFormat == GL_RGB);
+ if (wScale == 1 && hScale == 1) {
+ GLint i, n = dstWidth * dstHeight;
+ const GLushort *texel = (const GLushort *) srcImage;
+ for (i = 0; i < n; i++) {
+ const GLushort tex = *texel++;
+ *dstImage++ = R5G6B5toRed[tex];
+ *dstImage++ = R5G6B5toGreen[tex];
+ *dstImage++ = R5G6B5toBlue[tex];
+ }
+ }
+ else {
+ /* rescale */
+ const GLushort *src16 = (const GLushort *) srcImage;
+ GLint row, col;
+ for (row = 0; row < dstHeight; row++) {
+ GLint srcRow = row * hScale;
+ for (col = 0; col < dstWidth; col++) {
+ GLint srcCol = col * wScale;
+ const GLushort tex = src16[srcRow * srcWidth + srcCol];
+ *dstImage++ = R5G6B5toRed[tex];
+ *dstImage++ = R5G6B5toGreen[tex];
+ *dstImage++ = R5G6B5toBlue[tex];
+ }
+ }
+ }
+ break;
+ case MESA_A4_R4_G4_B4:
+ ASSERT(dstFormat == GL_RGBA);
+ if (wScale == 1 && hScale == 1) {
+ GLint i, n = dstWidth * dstHeight;
+ const GLushort *texel = (const GLushort *) srcImage;
+ for (i = 0; i < n; i++) {
+ const GLushort tex = *texel++;
+ *dstImage++ = A4R4G4B4toRed[tex];
+ *dstImage++ = A4R4G4B4toGreen[tex];
+ *dstImage++ = A4R4G4B4toBlue[tex];
+ *dstImage++ = A4R4G4B4toAlpha[tex];
+ }
+ }
+ else {
+ /* rescale */
+ const GLushort *src16 = (const GLushort *) srcImage;
+ GLint row, col;
+ for (row = 0; row < dstHeight; row++) {
+ GLint srcRow = row * hScale;
+ for (col = 0; col < dstWidth; col++) {
+ GLint srcCol = col * wScale;
+ const GLushort tex = src16[srcRow * srcWidth + srcCol];
+ *dstImage++ = A4R4G4B4toRed[tex];
+ *dstImage++ = A4R4G4B4toGreen[tex];
+ *dstImage++ = A4R4G4B4toBlue[tex];
+ *dstImage++ = A4R4G4B4toAlpha[tex];
+ }
+ }
+ }
+ break;
+ case MESA_A1_R5_G5_B5:
+ ASSERT(dstFormat == GL_RGBA);
+ if (wScale == 1 && hScale == 1) {
+ GLint i, n = dstWidth * dstHeight;
+ const GLushort *texel = (const GLushort *) srcImage;
+ for (i = 0; i < n; i++) {
+ const GLushort tex = *texel++;
+ *dstImage++ = A1R5G5B5toRed[tex];
+ *dstImage++ = A1R5G5B5toGreen[tex];
+ *dstImage++ = A1R5G5B5toBlue[tex];
+ *dstImage++ = A1R5G5B5toAlpha[tex];
+ }
+ }
+ else {
+ /* rescale */
+ const GLushort *src16 = (const GLushort *) srcImage;
+ GLint row, col;
+ for (row = 0; row < dstHeight; row++) {
+ GLint srcRow = row * hScale;
+ for (col = 0; col < dstWidth; col++) {
+ GLint srcCol = col * wScale;
+ const GLushort tex = src16[srcRow * srcWidth + srcCol];
+ *dstImage++ = A1R5G5B5toRed[tex];
+ *dstImage++ = A1R5G5B5toGreen[tex];
+ *dstImage++ = A1R5G5B5toBlue[tex];
+ *dstImage++ = A1R5G5B5toAlpha[tex];
+ }
+ }
+ }
+ break;
+ case MESA_A8_R8_G8_B8:
+ ASSERT(dstFormat == GL_RGBA);
+ if (wScale == 1 && hScale == 1) {
+ GLint i, n = dstWidth * dstHeight;
+ const GLushort *texel = (const GLushort *) srcImage;
+ for (i = 0; i < n; i++) {
+ const GLuint tex = *texel++;
+ *dstImage++ = (tex >> 16) & 0xff; /* R */
+ *dstImage++ = (tex >> 8) & 0xff; /* G */
+ *dstImage++ = (tex ) & 0xff; /* B */
+ *dstImage++ = (tex >> 24) & 0xff; /* A */
+ }
+ }
+ else {
+ /* rescale */
+ const GLushort *src16 = (const GLushort *) srcImage;
+ GLint row, col;
+ for (row = 0; row < dstHeight; row++) {
+ GLint srcRow = row * hScale;
+ for (col = 0; col < dstWidth; col++) {
+ GLint srcCol = col * wScale;
+ const GLuint tex = src16[srcRow * srcWidth + srcCol];
+ *dstImage++ = (tex >> 16) & 0xff; /* R */
+ *dstImage++ = (tex >> 8) & 0xff; /* G */
+ *dstImage++ = (tex ) & 0xff; /* B */
+ *dstImage++ = (tex >> 24) & 0xff; /* A */
+ }
+ }
+ }
+ break;
+ default:
+ gl_problem(NULL, "bad srcFormat in _mesa_uncovert_teximage()");
+ }
+}
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