From 2965df485bb87c6b525cc406c7d8d4a355fd067f Mon Sep 17 00:00:00 2001
From: Hayden Kowalchuk <hayden@hkowsoftware.com>
Date: Tue, 13 Aug 2019 18:17:11 -0400
Subject: [PATCH] fix: minor texture changes for GluBuildMipmaps

---
 GL/glu.c     | 112 +++++++++++++++++++++++++++++++++++++++++++++++++++
 GL/texture.c |   8 ++--
 2 files changed, 116 insertions(+), 4 deletions(-)

diff --git a/GL/glu.c b/GL/glu.c
index ae9a590..59834ea 100644
--- a/GL/glu.c
+++ b/GL/glu.c
@@ -1,5 +1,6 @@
 #include <math.h>
 #include "private.h"
+#include "glext.h"
 
 /* Set the Perspective */
 void APIENTRY gluPerspective(GLfloat angle, GLfloat aspect,
@@ -17,3 +18,114 @@ void APIENTRY gluPerspective(GLfloat angle, GLfloat aspect,
 void APIENTRY gluOrtho2D(GLdouble left, GLdouble right, GLdouble bottom, GLdouble top) {
     glOrtho(left, right, bottom, top, -1.0f, 1.0f);
 }
+
+extern GLuint _determinePVRFormat(GLint internalFormat, GLenum type);
+extern GLint _determineStride(GLenum format, GLenum type);
+extern GLint _cleanInternalFormat(GLint internalFormat);
+
+
+GLint APIENTRY gluScaleImage(GLenum format,
+		    GLsizei src_width, GLsizei src_height,
+		    GLenum src_type, const GLvoid *src,
+		    GLsizei dst_width, GLsizei dst_height,
+		    GLenum dst_type, GLvoid *dst)
+{
+
+    /* Calculate the format that we need to convert the data to */
+    GLuint dst_format = _determinePVRFormat(format, src_type);
+    GLuint pvr_format = _determinePVRFormat(format, dst_type);
+	
+    int i;
+
+	if (src_width == dst_width &&
+	    src_height == dst_height &&
+	    src_type == dst_type) {
+		memcpy(dst, src, dst_width * dst_height * 2 /* shorts? */);
+		return 0;
+	} else {
+        return 0;
+    }
+#if 0
+	image = malloc(src_width * src_height * sizeof(pix_t));
+	if (image == NULL)
+		return GLU_OUT_OF_MEMORY;
+	for(i = 0; i < src_height; i++)
+		(*srcfmt->unpack)(srcfmt,
+				  src + i * src_width * srcfmt->size,
+				  &image[i * src_width],
+				  src_width);
+
+	if (src_width != dst_width)
+		image = rescale_horiz(image, src_width, dst_width, src_height);
+
+	if (src_height != dst_height)
+		image = rescale_vert(image, dst_width, src_height, dst_height);
+
+	if (image == NULL)
+		return GL_OUT_OF_MEMORY;
+
+	for(i = 0; i < dst_height; i++)
+		(*dstfmt->pack)(dstfmt,
+				&image[i * dst_width],
+				dst + i * dst_width * dstfmt->size,
+				dst_width);
+	free(image);
+    #endif
+	return 0;
+}
+
+GLint APIENTRY gluBuild2DMipmaps( GLenum target,GLint internalFormat, GLsizei width, GLsizei height,
+			 GLenum format,	 GLenum type, const void *data )
+{
+    #if 0
+	GLsizei tw, th;
+	const void *src;
+	void *dst;
+	int level, levels;
+	GLint maxtex;
+
+	tw = width;
+	th = height;
+
+	glGetIntegerv(GL_MAX_TEXTURE_SIZE, &maxtex);
+
+	while(tw > maxtex)
+		tw /= 2;
+	while(th > maxtex)
+		th /= 2;	
+
+	levels = 1 + floor(log2(tw));
+	level = 1 + floor(log2(th));
+	if (level > levels)
+		levels = level;
+
+	src = data;
+	dst = NULL;
+
+	for(level = 0; level <= levels; level++) {
+		dst = malloc(tw * th * 2 /*shorts so 2 bytes*/);
+
+		gluScaleImage(format,
+			      width, height, type, src,
+			      tw, th, type, dst);
+
+		glTexImage2D(target, level, internalFormat, 
+			     tw, th, 0, format, type, dst);
+
+		if (src != data)
+			free((void *)src);
+		src = dst;
+		width = tw;
+		height = th;
+
+		if (tw > 1)
+			tw /= 2;
+		if (th > 1)
+			th /= 2;
+	}
+	free(dst);
+    #endif
+    glTexImage2D(target, 0, internalFormat, width, height, 0, format, type, data);
+    glGenerateMipmapEXT(target);
+	return 0;
+}
\ No newline at end of file
diff --git a/GL/texture.c b/GL/texture.c
index cf8971e..6733f8e 100644
--- a/GL/texture.c
+++ b/GL/texture.c
@@ -21,7 +21,7 @@ GLubyte ACTIVE_TEXTURE = 0;
 
 static TexturePalette* SHARED_PALETTES[4] = {NULL, NULL, NULL, NULL};
 
-static GLuint _determinePVRFormat(GLint internalFormat, GLenum type);
+GLuint _determinePVRFormat(GLint internalFormat, GLenum type);
 
 #define PACK_ARGB8888(a,r,g,b) ( ((a & 0xFF) << 24) | ((r & 0xFF) << 16) | ((g & 0xFF) << 8) | (b & 0xFF) )
 
@@ -139,7 +139,7 @@ GLubyte _glGetActiveTexture() {
     return ACTIVE_TEXTURE;
 }
 
-static GLint _determineStride(GLenum format, GLenum type) {
+ GLint _determineStride(GLenum format, GLenum type) {
     switch(type) {
     case GL_BYTE:
     case GL_UNSIGNED_BYTE:
@@ -563,7 +563,7 @@ void APIENTRY glCompressedTexImage2DARB(GLenum target,
         sq_cpy(active->data, data, imageSize);
 }
 
-static GLint _cleanInternalFormat(GLint internalFormat) {
+GLint _cleanInternalFormat(GLint internalFormat) {
     switch (internalFormat) {
     case GL_COLOR_INDEX4_EXT:
         return GL_COLOR_INDEX4_EXT;
@@ -637,7 +637,7 @@ static GLint _cleanInternalFormat(GLint internalFormat) {
     }
 }
 
-static GLuint _determinePVRFormat(GLint internalFormat, GLenum type) {
+ GLuint _determinePVRFormat(GLint internalFormat, GLenum type) {
     /* Given a cleaned internalFormat, return the Dreamcast format
      * that can hold it
      */