OpenGL 1.0 fallback attempt

src/Graphics_GL1.c

@@ -654,6 +654,51 @@ static void APIENTRY legacy_bufferSubData(GLenum target, cc_uintptr offset, cc_u
 }
 
 
+static void APIENTRY gl10_bindTexture(GLenum target, GLuint texture) {
+	
+}
+static void APIENTRY gl10_deleteTexture(GLsizei n, const GLuint* textures) {
+
+}
+static void APIENTRY gl10_genTexture(GLsizei n, GLuint* textures) {
+
+}
+static void APIENTRY gl10_texImage(GLenum target, GLint level, GLint internalformat, GLsizei width, GLsizei height, GLint border, GLenum format, GLenum type, const GLvoid* pixels) {
+	
+}
+static void APIENTRY gl10_texSubImage(GLenum target, GLint level, GLint xoffset, GLint yoffset, GLsizei width, GLsizei height, GLenum format, GLenum type, const GLvoid* pixels) {
+	
+}
+
+static cc_uint8* gl10_vb;
+static void APIENTRY gl10_drawElements(GLenum mode, GLsizei count, GLenum type, const GLvoid* indices) {
+	/* TODO */
+	int i;
+	glBegin(GL_QUADS);
+
+	if (gfx_format == VERTEX_FORMAT_TEXTURED) {
+		struct VertexTextured* src = (struct VertexTextured*)gl10_vb;
+		for (i = 0; i < count; i++, src++) {
+			glVertex3f(src->x, src->y, src->z);
+		}
+	} else {
+		struct VertexColoured* src = (struct VertexColoured*)gl10_vb;
+		for (i = 0; i < count; i++, src++) {
+			glVertex3f(src->x, src->y, src->z);
+		}
+	}
+
+	glEnd();
+}
+static void APIENTRY gl10_colorPointer(GLint size, GLenum type, GLsizei stride, GLpointer offset) {
+}
+static void APIENTRY gl10_texCoordPointer(GLint size, GLenum type, GLsizei stride, GLpointer offset) {
+}
+static void APIENTRY gl10_vertexPointer(GLint size, GLenum type, GLsizei stride, GLpointer offset) {
+	gl10_vb = cur_vb->data + offset;
+}
+
+
 static void APIENTRY gl11_drawElements(GLenum mode, GLsizei count, GLenum type, const GLvoid* indices) {
 	_realDrawElements(mode, count, type, (cc_uintptr)indices + cur_ib->data);
 }
@@ -686,6 +731,19 @@ static void FallbackOpenGL(void) {
 
 	_glDrawElements    = gl11_drawElements;    _glColorPointer  = gl11_colorPointer;
 	_glTexCoordPointer = gl11_texCoordPointer; _glVertexPointer = gl11_vertexPointer;
+
+	/* OpenGL 1.0 fallback support */
+	if (_realDrawElements) return;
+	Window_ShowDialog("Performance warning", "OpenGL 1.0 only support, expect awful performance");
+
+	_glDrawElements    = gl10_drawElements;    _glColorPointer  = gl10_colorPointer;
+	_glTexCoordPointer = gl10_texCoordPointer; _glVertexPointer = gl10_vertexPointer;
+
+	_glBindTexture    = gl10_bindTexture;
+	_glGenTextures    = gl10_genTexture;
+	_glDeleteTextures = gl10_deleteTexture;
+	_glTexImage2D     = gl10_texImage;
+	_glTexSubImage2D  = gl10_texSubImage;
 }
 #else
 /* No point in even trying for other systems */

src/_GL1Funcs.h

@@ -48,9 +48,14 @@ GL_FUNC(void,           glGetFloatv)(GLenum pname, GLfloat* params);
 GL_FUNC(void,           glGetIntegerv)(GLenum pname, GLint* params);
 GL_FUNC(const GLubyte*, glGetString)(GLenum name);
 
-/* Display list functions */
+/* Legacy display list functions */
 GL_FUNC(void,   glCallList)(GLuint list);
 GL_FUNC(void,   glDeleteLists)(GLuint list, GLsizei range);
 GL_FUNC(GLuint, glGenLists)(GLsizei range);
 GL_FUNC(void,   glNewList)(GLuint list, GLenum mode);
 GL_FUNC(void,   glEndList)(void);
+
+/* Legacy vertex draw functions */
+GL_FUNC(void,   glBegin)(GLenum mode);
+GL_FUNC(void,   glEnd)(void);
+GL_FUNC(void,   glVertex3f)(float x, float y, float z);

src/_GLShared.h

@@ -113,17 +113,17 @@ static CC_NOINLINE void UpdateTextureSlow(int x, int y, struct Bitmap* part, int
 	CopyTextureData(ptr, part->width << 2, part, rowWidth << 2);
 
 	if (full) {
-		glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, part->width, part->height, 0, PIXEL_FORMAT, TRANSFER_FORMAT, ptr);
+		_glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, part->width, part->height, 0, PIXEL_FORMAT, TRANSFER_FORMAT, ptr);
 	} else {
-		glTexSubImage2D(GL_TEXTURE_2D, 0, x, y, part->width, part->height, PIXEL_FORMAT, TRANSFER_FORMAT, ptr);
+		_glTexSubImage2D(GL_TEXTURE_2D, 0, x, y, part->width, part->height, PIXEL_FORMAT, TRANSFER_FORMAT, ptr);
 	}
 	if (count > UPDATE_FAST_SIZE) Mem_Free(ptr);
 }
 
 static GfxResourceID Gfx_AllocTexture(struct Bitmap* bmp, int rowWidth, cc_uint8 flags, cc_bool mipmaps) {
-	GLuint texId;
+	GfxResourceID texId = NULL;
-	glGenTextures(1, &texId);
+	_glGenTextures(1, (GLuint*)&texId);
-	glBindTexture(GL_TEXTURE_2D, texId);
+	_glBindTexture(GL_TEXTURE_2D, ptr_to_uint(texId));
 	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
 
 	if (mipmaps) {
@@ -143,11 +143,11 @@ static GfxResourceID Gfx_AllocTexture(struct Bitmap* bmp, int rowWidth, cc_uint8
 	}
 
 	if (mipmaps) Gfx_DoMipmaps(0, 0, bmp, rowWidth, false);
-	return uint_to_ptr(texId);
+	return texId;
 }
 
 void Gfx_UpdateTexture(GfxResourceID texId, int x, int y, struct Bitmap* part, int rowWidth, cc_bool mipmaps) {
-	glBindTexture(GL_TEXTURE_2D, ptr_to_uint(texId));
+	_glBindTexture(GL_TEXTURE_2D, ptr_to_uint(texId));
 
 	if (part->width == rowWidth) {
 		_glTexSubImage2D(GL_TEXTURE_2D, 0, x, y, part->width, part->height, PIXEL_FORMAT, TRANSFER_FORMAT, part->scan0);
@@ -160,7 +160,7 @@ void Gfx_UpdateTexture(GfxResourceID texId, int x, int y, struct Bitmap* part, i
 
 void Gfx_DeleteTexture(GfxResourceID* texId) {
 	GLuint id = ptr_to_uint(*texId);
-	if (id) glDeleteTextures(1, &id);
+	if (id) _glDeleteTextures(1, &id);
 	*texId = 0;
 }