TINYGL: added tglAlphaTest stubs

engines/grim/gfx_tinygl.cpp

@@ -862,10 +862,10 @@ void GfxTinyGL::drawSprite(const Sprite *sprite) {
 	tglDisable(TGL_LIGHTING);
 
 	if (sprite->_alphaTest) {
-		//tglEnable(TGL_ALPHA_TEST);
-		//tglAlphaFunc(TGL_GEQUAL, g_grim->getGameType() == GType_MONKEY4 ? 0.1f : 0.5f);
+		tglEnable(TGL_ALPHA_TEST);
+		tglAlphaFunc(TGL_GEQUAL, g_grim->getGameType() == GType_MONKEY4 ? 0.1f : 0.5f);
 	} else {
-		//tglDisable(TGL_ALPHA_TEST);
+		tglDisable(TGL_ALPHA_TEST);
 	}
 
 	if (sprite->_writeDepth) {

graphics/tinygl/Changelog

@@ -25,5 +25,6 @@ The changes made from the original version of TinyGL 0.4 are:
 * Heavily refactored the triangle and line drawing routines
 * Renamed ZBuffer into FrameBuffer and moved all the external C functions as member functions.
 * Added implementation of glBlendFunc and support for 8-bit alpha.
+* Added implementation of glAlphaTestFunc.
 
 For more information refer to log changes in github: https://github.com/residualvm/residualvm

graphics/tinygl/api.cpp

@@ -185,6 +185,16 @@ void tglBlendFunc(TGLenum sfactor, TGLenum dfactor) {
 	TinyGL::gl_add_op(p);
 }
 
+void tglAlphaFunc(TGLenum func, float ref) {
+	TinyGL::GLParam p[3];
+
+	p[0].op = TinyGL::OP_AlphaFunc;
+	p[1].i = func;
+	p[2].f = ref;
+
+	TinyGL::gl_add_op(p);
+}
+
 void tglPolygonMode(int face, int mode) {
 	TinyGL::GLParam p[3];
 

graphics/tinygl/get.cpp

@@ -31,8 +31,11 @@ void tglGetIntegerv(int pname, int *params) {
 	case TGL_BLEND:
 		*params = c->enableBlend;
 		break;
+	case TGL_ALPHA_TEST:
+		*params = c->_alphaTestEnabled;
+		break;
 	default:
-		error("glGet: option not implemented");
+		error("tglGet: option not implemented");
 		break;
 	}
 }

graphics/tinygl/gl.h

@@ -798,6 +798,7 @@ void tglFrontFace(int mode);
 void tglColorMask(TGLboolean r, TGLboolean g, TGLboolean b, TGLboolean a);
 void tglDepthMask(int enableWrite);
 void tglBlendFunc(TGLenum sfactor, TGLenum dfactor);
+void tglAlphaFunc(TGLenum func, float ref);
 
 void tglSetShadowMaskBuf(unsigned char *buf);
 void tglSetShadowColor(unsigned char r, unsigned char g, unsigned char b);

graphics/tinygl/init.cpp

@@ -126,8 +126,13 @@ void glInit(void *zbuffer1) {
 	c->render_mode = TGL_RENDER;
 	c->select_buffer = NULL;
 	c->name_stack_size = 0;
+
+	// blending
 	c->enableBlend = false;
 
+	// alpha test
+	c->_alphaTestEnabled = false;
+
 	// matrix
 	c->matrix_mode = 0;
 
@@ -146,8 +151,11 @@ void glInit(void *zbuffer1) {
 	tglLoadIdentity();
 	tglMatrixMode(TGL_MODELVIEW);
 	tglLoadIdentity();
+
 	tglBlendFunc(TGL_SRC_ALPHA, TGL_ONE_MINUS_SRC_ALPHA);
 
+	tglAlphaFunc(TGL_ALWAYS, 0.f);
+
 	c->matrix_model_projection_updated = 1;
 
 	// opengl 1.1 arrays

graphics/tinygl/misc.cpp

@@ -61,6 +61,10 @@ void glopEnableDisable(GLContext *c, GLParam *p) {
 	case TGL_DEPTH_TEST:
 		c->depth_test = v;
 		break;
+	case TGL_ALPHA_TEST:
+		c->_alphaTestEnabled = v;
+		c->fb->enableAlphaTest(v);
+		break;
 	case TGL_BLEND:
 		c->enableBlend = v;
 		c->fb->enableBlending(v);
@@ -111,6 +115,12 @@ void glopBlendFunc(GLContext *c, GLParam *p) {
 	c->fb->setBlendingFactors(sfactor, dfactor);
 }
 
+void glopAlphaFunc(GLContext *c, GLParam *p) {
+	TGLenum func = p[1].i;
+	float ref = p[2].i;
+	c->fb->setAlphaTestFunc(func, ref);
+}
+
 void glopShadeModel(GLContext *c, GLParam *p) {
 	int code = p[1].i;
 	c->current_shade_model = code;

graphics/tinygl/opinfo.h

@@ -52,6 +52,7 @@ ADD_OP(PolygonMode, 2, "%C %C")
 ADD_OP(ColorMask, 1, "%08x")
 ADD_OP(DepthMask, 1, "%d")
 ADD_OP(BlendFunc, 2, "%d %d")
+ADD_OP(AlphaFunc, 2, "%d %f")
 
 ADD_OP(CallList, 1, "%d")
 ADD_OP(Hint, 2, "%C %C")

graphics/tinygl/zbuffer.cpp

@@ -86,6 +86,7 @@ FrameBuffer::FrameBuffer(int width, int height, const Graphics::PixelBuffer &fra
 	this->buffer.pbuf = this->pbuf.getRawBuffer();
 	this->buffer.zbuf = this->zbuf;
 	_blendingEnabled = false;
+	_alphaTestEnabled = false;
 }
 
 FrameBuffer::~FrameBuffer() {
@@ -171,4 +172,13 @@ void FrameBuffer::enableBlending(bool enable) {
 	_blendingEnabled = enable;
 }
 
+void FrameBuffer::setAlphaTestFunc(int func, float ref) {
+	_alphaTestFunc = func;
+	_alphaTestRefVal = (int)(ref * 255);
+}
+
+void FrameBuffer::enableAlphaTest(bool enable) {
+	_alphaTestEnabled = enable;
+}
+
 } // end of namespace TinyGL

graphics/tinygl/zbuffer.h

@@ -199,8 +199,10 @@ struct FrameBuffer {
 		pbuf.copyBuffer(0, xsize * ysize, buf);
 	}
 
-	void enableBlending(bool enableBlending);
+	void enableBlending(bool enable);
 	void setBlendingFactors(int sfactor, int dfactor);
+	void enableAlphaTest(bool enable);
+	void setAlphaTestFunc(int func, float ref);
 	void enableDepthWrite(bool enable) {
 		this->_depthWrite = enable;
 	}
@@ -261,6 +263,9 @@ private:
 	bool _blendingEnabled;
 	int _sourceBlendingFactor;
 	int _destinationBlendingFactor;
+	bool _alphaTestEnabled;
+	int _alphaTestFunc;
+	int _alphaTestRefVal;
 };
 
 // memory.c

graphics/tinygl/zgl.h

@@ -210,7 +210,6 @@ struct GLContext {
 	gl_draw_triangle_func draw_triangle_front, draw_triangle_back;
 
 	// selection
-	bool enableBlend;
 	int render_mode;
 	unsigned int *select_buffer;
 	int select_size;
@@ -275,6 +274,12 @@ struct GLContext {
 	// depth test
 	int depth_test;
 	int color_mask;
+
+	// alpha test
+	bool _alphaTestEnabled;
+
+	// blending
+	bool enableBlend;
 };
 
 extern GLContext *gl_ctx;