Fix depth issues

GL/draw.c

@@ -1172,10 +1172,14 @@ GL_FORCE_INLINE void divide(SubmissionTarget* target) {
         float f = MATH_Fast_Invert(vertex->w);
         vertex->xyz[0] *= f;
         vertex->xyz[1] *= f;
-        vertex->xyz[2] = vertex->w;
 
-        /* FIXME: Consider taking glDepthRange into account. PVR is designed to use invW rather
+        /* We have to use 1/z instead of reusing 1/w from above because
-         * than Z which is unlike most GPUs - this apparently provides advantages.
+         * orthographic projections always product a W == 1 and so would not
+         * correctly render ordered transparent surfaces */
+        vertex->xyz[2] = MATH_Fast_Invert(vertex->xyz[2]);
+
+        /* FIXME: Consider taking glDepthRange into account. PVR is designed to use 1/w
+         * which is unlike most GPUs - this apparently provides advantages.
          *
          * This can be done (if Z is between -1 and 1) with:
          *

GL/state.c

@@ -63,17 +63,17 @@ static int _calc_pvr_depth_test() {
         case GL_NEVER:
             return PVR_DEPTHCMP_NEVER;
         case GL_LESS:
-            return PVR_DEPTHCMP_LESS;
+            return PVR_DEPTHCMP_GREATER;
         case GL_EQUAL:
             return PVR_DEPTHCMP_EQUAL;
         case GL_LEQUAL:
-            return PVR_DEPTHCMP_LEQUAL;
+            return PVR_DEPTHCMP_GEQUAL;
         case GL_GREATER:
-            return PVR_DEPTHCMP_GREATER;
+            return PVR_DEPTHCMP_LESS;
         case GL_NOTEQUAL:
             return PVR_DEPTHCMP_NOTEQUAL;
         case GL_GEQUAL:
-            return PVR_DEPTHCMP_GEQUAL;
+            return PVR_DEPTHCMP_LEQUAL;
         break;
         case GL_ALWAYS:
         default:

samples/depth_funcs/main.c

@@ -7,7 +7,7 @@ void InitGL(int Width, int Height)	        // We call this right after our OpenG
 {
     glClearColor(0.0f, 0.0f, 0.0f, 0.0f);		// This Will Clear The Background Color To Black
     glClearDepth(1.0);				// Enables Clearing Of The Depth Buffer
-    glDepthFunc(GL_LESS);				// The Type Of Depth Test To Do
+    glDepthFunc(GL_LEQUAL);				// The Type Of Depth Test To Do
     glEnable(GL_DEPTH_TEST);			// Enables Depth Testing
     glShadeModel(GL_SMOOTH);			// Enables Smooth Color Shading
 
@@ -60,22 +60,47 @@ void DrawGLScene()
     glDepthFunc(GL_LEQUAL);
     DrawSquare(1.0, 1, 0, 0, -5.0f);
 
+    glPushMatrix();
+        glTranslatef(0, -1.5, 0);
+        DrawSquare(1.0, 1, 0, 0, -4.9f);
+    glPopMatrix();
+
     glTranslatef(1.1, 0, 0);
     glDepthFunc(GL_EQUAL);
     DrawSquare(1.0, 1, 0, 0, -5.0f);
 
+    glPushMatrix();
+        glTranslatef(0, -1.5, 0);
+        DrawSquare(1.0, 1, 0, 0, -5.0f);
+    glPopMatrix();
+
     glTranslatef(1.1, 0, 0);
     glDepthFunc(GL_GEQUAL);
     DrawSquare(1.0, 1, 0, 0, -5.0f);
 
+    glPushMatrix();
+        glTranslatef(0, -1.5, 0);
+        DrawSquare(1.0, 1, 0, 0, -5.1f);
+    glPopMatrix();
+
     glTranslatef(1.1, 0, 0);
     glDepthFunc(GL_LESS);
     DrawSquare(1.0, 1, 0, 0, -4.9f);
 
+    glPushMatrix();
+        glTranslatef(0, -1.5, 0);
+        DrawSquare(1.0, 1, 0, 0, -4.8f);
+    glPopMatrix();
+
     glTranslatef(1.1, 0, 0);
     glDepthFunc(GL_GREATER);
     DrawSquare(1.0, 1, 0, 0, -5.1f);
 
+    glPushMatrix();
+        glTranslatef(0, -1.5, 0);
+        DrawSquare(1.0, 1, 0, 0, -5.2f);
+    glPopMatrix();
+
     // swap buffers to display, since we're double buffered.
     glKosSwapBuffers();
 }

samples/zclip/main.c

@@ -137,9 +137,9 @@ void InitGL(int Width, int Height)	        // We call this right after our OpenG
 {
     LoadGLTextures();
 
-    glClearColor(0.0f, 0.0f, 0.0f, 0.0f);		// This Will Clear The Background Color To Black
+    glClearColor(0.0f, 0.0f, 0.0f, 1.0f);		// This Will Clear The Background Color To Black
     glClearDepth(1.0);				// Enables Clearing Of The Depth Buffer
-    glDepthFunc(GL_LESS);				// The Type Of Depth Test To Do
+    glDepthFunc(GL_LEQUAL);				// The Type Of Depth Test To Do
     glEnable(GL_DEPTH_TEST);			// Enables Depth Testing
     glShadeModel(GL_SMOOTH);			// Enables Smooth Color Shading
     glEnable(GL_TEXTURE_2D);