Merge branch 'alpha-test' into 'master'

Implement glAlphaFunc and glEnable(GL_ALPHA_TEST)

See merge request simulant/GLdc!36

GL/flush.c

@@ -41,7 +41,7 @@ static void pvr_list_submit(void *src, int n) {
 static void _glInitPVR() {
     pvr_init_params_t params = {
         /* Enable opaque and translucent polygons with size 32 and 32 */
-        { PVR_BINSIZE_32, PVR_BINSIZE_0, PVR_BINSIZE_32, PVR_BINSIZE_0, PVR_BINSIZE_32 },
+        {PVR_BINSIZE_32, PVR_BINSIZE_0, PVR_BINSIZE_32, PVR_BINSIZE_0, PVR_BINSIZE_32},
         PVR_VERTEX_BUF_SIZE, /* Vertex buffer size */
         0, /* No DMA */
         0, /* No FSAA */
@@ -55,6 +55,8 @@ static void _glInitPVR() {
 PolyList* _glActivePolyList() {
     if(_glIsBlendingEnabled()) {
         return &TR_LIST;
+    } else if(_glIsAlphaTestEnabled()) {
+        return &PT_LIST;
     } else {
         return &OP_LIST;
     }

GL/private.h

@@ -152,6 +152,8 @@ GLboolean _glIsSharedTexturePaletteEnabled();
 void _glApplyColorTable(TexturePalette *palette);
 
 GLboolean _glIsBlendingEnabled();
+GLboolean _glIsAlphaTestEnabled();
+
 GLboolean _glIsMipmapComplete(const TextureObject* obj);
 GLubyte* _glGetMipmapLocation(TextureObject* obj, GLuint level);
 GLuint _glGetMipmapLevelCount(TextureObject* obj);

GL/state.c

@@ -30,6 +30,9 @@ static GLboolean COLOR_MATERIAL_ENABLED = GL_FALSE;
 /* Is the shared texture palette enabled? */
 static GLboolean SHARED_PALETTE_ENABLED = GL_FALSE;
 
+static GLboolean ALPHA_TEST_ENABLED = GL_FALSE;
+
+
 GLboolean _glIsSharedTexturePaletteEnabled() {
     return SHARED_PALETTE_ENABLED;
 }
@@ -84,6 +87,10 @@ GLboolean _glIsBlendingEnabled() {
     return BLEND_ENABLED;
 }
 
+GLboolean _glIsAlphaTestEnabled() {
+    return ALPHA_TEST_ENABLED;
+}
+
 static int _calcPVRBlendFactor(GLenum factor) {
     switch(factor) {
     case GL_ZERO:
@@ -311,6 +318,9 @@ GLAPI void APIENTRY glEnable(GLenum cap) {
             SHARED_PALETTE_ENABLED = GL_TRUE;
         }
         break;
+        case GL_ALPHA_TEST: {
+            ALPHA_TEST_ENABLED = GL_TRUE;
+        } break;
         case GL_LIGHT0:
         case GL_LIGHT1:
         case GL_LIGHT2:
@@ -362,6 +372,9 @@ GLAPI void APIENTRY glDisable(GLenum cap) {
             SHARED_PALETTE_ENABLED = GL_FALSE;
         }
         break;
+        case GL_ALPHA_TEST: {
+            ALPHA_TEST_ENABLED = GL_FALSE;
+        } break;
         case GL_LIGHT0:
         case GL_LIGHT1:
         case GL_LIGHT2:
@@ -457,8 +470,20 @@ GLAPI void APIENTRY glBlendFunc(GLenum sfactor, GLenum dfactor) {
     _updatePVRBlend(&GL_CONTEXT);
 }
 
-void glAlphaFunc(GLenum func, GLclampf ref) {
-    ;
+#define PT_ALPHA_REF 0x011c
+
+GLAPI void APIENTRY glAlphaFunc(GLenum func, GLclampf ref) {
+    GLenum validFuncs[] = {
+        GL_GREATER,
+        0
+    };
+
+    if(_glCheckValidEnum(func, validFuncs, __func__) != 0) {
+        return;
+    }
+
+    GLubyte val = (GLubyte)(ref * 255.0f);
+    PVR_SET(PT_ALPHA_REF, val);
 }
 
 void glLineWidth(GLfloat width) {

GL/texture.c

@@ -822,7 +822,7 @@ void APIENTRY glTexImage2D(GLenum target, GLint level, GLint internalFormat,
     }
 
     if(!TEXTURE_UNITS[ACTIVE_TEXTURE]) {
-        _glKosThrowError(GL_INVALID_OPERATION, "glTexImage2D");
+        _glKosThrowError(GL_INVALID_OPERATION, __func__);
     }
 
     GLboolean isPaletted = (internalFormat == GL_COLOR_INDEX8_EXT) ? GL_TRUE : GL_FALSE;

samples/paletted_pcx/main.c

@@ -15,7 +15,7 @@ KOS_INIT_ROMDISK(romdisk);
 /* floats for x rotation, y rotation, z rotation */
 float xrot, yrot, zrot;
 
-int textures[2];
+int textures[3];
 
 typedef struct {
     unsigned int height;
@@ -131,9 +131,13 @@ int LoadPalettedPCX(const char* filename, Image* image) {
 // Load Bitmaps And Convert To Textures
 void LoadGLTextures() {
     // Load Texture
-    Image image1;
+    Image image1, image2;
 
-    if (!LoadPalettedPCX("/rd/NeHe.pcx", &image1)) {
+    if(!LoadPalettedPCX("/rd/NeHe.pcx", &image1)) {
+        exit(1);
+    }
+
+    if(!LoadPalettedPCX("/rd/NeHe-Alpha.pcx", &image2)) {
         exit(1);
     }
 
@@ -154,7 +158,7 @@ void LoadGLTextures() {
     glColorTableEXT(GL_SHARED_TEXTURE_PALETTE_1_KOS, GL_RGBA8, image1.palette_width, GL_RGB, GL_UNSIGNED_BYTE, inversed_palette);
 
     // Create Texture
-    glGenTextures(2, textures);
+    glGenTextures(3, textures);
     glBindTexture(GL_TEXTURE_2D, textures[0]);   // 2d texture (x and y size)
 
     glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MAG_FILTER, GL_LINEAR); // scale linearly when image bigger than texture
@@ -165,7 +169,6 @@ void LoadGLTextures() {
     glTexImage2D(GL_TEXTURE_2D, 0, GL_COLOR_INDEX8_EXT, image1.width, image1.height, 0, GL_COLOR_INDEX, GL_UNSIGNED_BYTE, image1.data);
 
     glBindTexture(GL_TEXTURE_2D, textures[1]);   // 2d texture (x and y size)
-
     glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MAG_FILTER, GL_LINEAR); // scale linearly when image bigger than texture
     glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MIN_FILTER, GL_LINEAR); // scale linearly when image smalled than texture
 
@@ -175,6 +178,22 @@ void LoadGLTextures() {
     // 2d texture, level of detail 0 (normal), 3 components (red, green, blue), x size from image, y size from image,
     // border 0 (normal), rgb color data, unsigned byte data, and finally the data itself.
     glTexImage2D(GL_TEXTURE_2D, 0, GL_COLOR_INDEX8_EXT, image1.width, image1.height, 0, GL_COLOR_INDEX, GL_UNSIGNED_BYTE, image1.data);
+
+    glBindTexture(GL_TEXTURE_2D, textures[2]);
+    glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MAG_FILTER, GL_NEAREST);
+    glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MIN_FILTER, GL_NEAREST);
+
+    char* new_palette = (char*) malloc(image2.palette_width * 4);
+    for(i = 0; i < image2.palette_width; ++i) {
+        new_palette[(i * 4) + 0] = image2.palette[(i * 3) + 0];
+        new_palette[(i * 4) + 1] = image2.palette[(i * 3) + 1];
+        new_palette[(i * 4) + 2] = image2.palette[(i * 3) + 2];
+        new_palette[(i * 4) + 3] = (i == 2) ? 0 : 255;
+    }
+
+    glColorTableEXT(GL_TEXTURE_2D, GL_RGBA8, image2.palette_width, GL_RGBA, GL_UNSIGNED_BYTE, new_palette);
+
+    glTexImage2D(GL_TEXTURE_2D, 0, GL_COLOR_INDEX8_EXT, image2.width, image2.height, 0, GL_COLOR_INDEX, GL_UNSIGNED_BYTE, image2.data);
 }
 
 /* A general OpenGL initialization function.  Sets all of the initial parameters. */
@@ -184,7 +203,7 @@ void InitGL(int Width, int Height)	        // We call this right after our OpenG
     glEnable(GL_TEXTURE_2D);
     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
 
@@ -262,7 +281,9 @@ void DrawGLScene()
     glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);		// Clear The Screen And The Depth Buffer
     glLoadIdentity();				// Reset The View
 
-    glTranslatef(-1.5f,0.0f,-5.0f);              // move 5 units into the screen.
+    glEnable(GL_SHARED_TEXTURE_PALETTE_EXT);
+
+    glTranslatef(-1.5f,0.0f,-8.0f);              // move 5 units into the screen.
 
     glPushMatrix();
         glRotatef(xrot,1.0f,0.0f,0.0f);		// Rotate On The X Axis
@@ -279,10 +300,25 @@ void DrawGLScene()
         DrawPolygon();
     glPopMatrix();
 
+    glDisable(GL_SHARED_TEXTURE_PALETTE_EXT);
+
     glBindTexture(GL_TEXTURE_2D, textures[1]);
     glTranslatef(3.0, 0, 0);
     DrawPolygon();
 
+    static float x = 0.0f;
+    x += 0.05f;
+    if(x > 5.0f) {
+        x = 0.0f;
+    }
+
+    glAlphaFunc(GL_GREATER, 0.666f);
+    glEnable(GL_ALPHA_TEST);
+    glBindTexture(GL_TEXTURE_2D, textures[2]);
+    glTranslatef(x - 3.0, 0, 3.0);
+    DrawPolygon();
+    glDisable(GL_ALPHA_TEST);
+
     xrot+=1.5f;		                // X Axis Rotation
     yrot+=1.5f;		                // Y Axis Rotation
     zrot+=1.5f; // Z Axis Rotation