Codechange: [OpenGL] Use generic vertex attributes in the shader program.

2 files changed, 29 insertions, 8 deletions

diff --git a/src/table/opengl_shader.h b/src/table/opengl_shader.h
index 43b2ca512..c59bcbcab 100644
--- a/src/table/opengl_shader.h
+++ b/src/table/opengl_shader.h
@@ -12,9 +12,11 @@
 /** Vertex shader that just passes colour and tex coords through. */
 static const char *_vertex_shader_direct[] = {
 	"#version 110\n",
+	"attribute vec2 position, colour_uv;",
+	"varying vec2 colour_tex_uv;",
 	"void main() {",
-	"  gl_TexCoord[0] = gl_MultiTexCoord0;",
-	"  gl_Position = gl_Vertex;",
+	"  colour_tex_uv = colour_uv;",
+	"  gl_Position = vec4(position, 0.0, 1.0);",
 	"}",
 };
 
@@ -22,7 +24,8 @@ static const char *_vertex_shader_direct[] = {
 static const char *_frag_shader_direct[] = {
 	"#version 110\n",
 	"uniform sampler2D colour_tex;",
+	"varying vec2 colour_tex_uv;",
 	"void main() {",
-	"  gl_FragColor = texture2D(colour_tex, gl_TexCoord[0].st);",
+	"  gl_FragColor = texture2D(colour_tex, colour_tex_uv);",
 	"}",
 };
diff --git a/src/video/opengl.cpp b/src/video/opengl.cpp
index dbf196164..2f92b2717 100644
--- a/src/video/opengl.cpp
+++ b/src/video/opengl.cpp
@@ -64,6 +64,11 @@ static PFNGLGETSHADERINFOLOGPROC _glGetShaderInfoLog;
 static PFNGLGETUNIFORMLOCATIONPROC _glGetUniformLocation;
 static PFNGLUNIFORM1IPROC _glUniform1i;
 
+static PFNGLGETATTRIBLOCATIONPROC _glGetAttribLocation;
+static PFNGLENABLEVERTEXATTRIBARRAYPROC _glEnableVertexAttribArray;
+static PFNGLDISABLEVERTEXATTRIBARRAYPROC _glDisableVertexAttribArray;
+static PFNGLVERTEXATTRIBPOINTERARBPROC _glVertexAttribPointer;
+
 /** A simple 2D vertex with just position and texture. */
 struct Simple2DVertex {
 	float x, y;
@@ -209,6 +214,11 @@ static bool BindShaderExtensions()
 		_glGetShaderInfoLog = (PFNGLGETSHADERINFOLOGPROC)GetOGLProcAddress("glGetShaderInfoLog");
 		_glGetUniformLocation = (PFNGLGETUNIFORMLOCATIONPROC)GetOGLProcAddress("glGetUniformLocation");
 		_glUniform1i = (PFNGLUNIFORM1IPROC)GetOGLProcAddress("glUniform1i");
+
+		_glGetAttribLocation = (PFNGLGETATTRIBLOCATIONPROC)GetOGLProcAddress("glGetAttribLocation");
+		_glEnableVertexAttribArray = (PFNGLENABLEVERTEXATTRIBARRAYPROC)GetOGLProcAddress("glEnableVertexAttribArray");
+		_glDisableVertexAttribArray = (PFNGLDISABLEVERTEXATTRIBARRAYPROC)GetOGLProcAddress("glDisableVertexAttribArray");
+		_glVertexAttribPointer = (PFNGLVERTEXATTRIBPOINTERARBPROC)GetOGLProcAddress("glVertexAttribPointer");
 	} else {
 		/* In the ARB extension programs and shaders are in the same object space. */
 		_glCreateProgram = (PFNGLCREATEPROGRAMPROC)GetOGLProcAddress("glCreateProgramObjectARB");
@@ -226,11 +236,17 @@ static bool BindShaderExtensions()
 		_glGetShaderInfoLog = (PFNGLGETSHADERINFOLOGPROC)GetOGLProcAddress("glGetInfoLogARB");
 		_glGetUniformLocation = (PFNGLGETUNIFORMLOCATIONPROC)GetOGLProcAddress("glGetUniformLocationARB");
 		_glUniform1i = (PFNGLUNIFORM1IPROC)GetOGLProcAddress("glUniform1iARB");
+
+		_glGetAttribLocation = (PFNGLGETATTRIBLOCATIONPROC)GetOGLProcAddress("glGetAttribLocationARB");
+		_glEnableVertexAttribArray = (PFNGLENABLEVERTEXATTRIBARRAYPROC)GetOGLProcAddress("glEnableVertexAttribArrayARB");
+		_glDisableVertexAttribArray = (PFNGLDISABLEVERTEXATTRIBARRAYPROC)GetOGLProcAddress("glDisableVertexAttribArrayARB");
+		_glVertexAttribPointer = (PFNGLVERTEXATTRIBPOINTERARBPROC)GetOGLProcAddress("glVertexAttribPointerARB");
 	}
 
 	return _glCreateProgram != nullptr && _glDeleteProgram != nullptr && _glLinkProgram != nullptr && _glGetProgramiv != nullptr && _glGetProgramInfoLog != nullptr &&
 		_glCreateShader != nullptr && _glDeleteShader != nullptr && _glShaderSource != nullptr && _glCompileShader != nullptr && _glAttachShader != nullptr &&
-		_glGetShaderiv != nullptr && _glGetShaderInfoLog != nullptr && _glGetUniformLocation != nullptr && _glUniform1i != nullptr;
+		_glGetShaderiv != nullptr && _glGetShaderInfoLog != nullptr && _glGetUniformLocation != nullptr && _glUniform1i != nullptr &&
+		_glGetAttribLocation != nullptr && _glEnableVertexAttribArray != nullptr && _glDisableVertexAttribArray != nullptr && _glVertexAttribPointer != nullptr;
 }
 
 /** Callback to receive OpenGL debug messages. */
@@ -417,10 +433,12 @@ const char *OpenGLBackend::Init()
 	if (glGetError() != GL_NO_ERROR) return "Can't generate VBO for fullscreen quad";
 
 	/* Set vertex state. */
-	glEnableClientState(GL_VERTEX_ARRAY);
-	glEnableClientState(GL_TEXTURE_COORD_ARRAY);
-	glVertexPointer(2, GL_FLOAT, sizeof(Simple2DVertex), (GLvoid *)offsetof(Simple2DVertex, x));
-	glTexCoordPointer(2, GL_FLOAT, sizeof(Simple2DVertex), (GLvoid *)offsetof(Simple2DVertex, u));
+	GLint loc_position = _glGetAttribLocation(this->vid_program, "position");
+	GLint colour_position = _glGetAttribLocation(this->vid_program, "colour_uv");
+	_glEnableVertexAttribArray(loc_position);
+	_glEnableVertexAttribArray(colour_position);
+	_glVertexAttribPointer(loc_position, 2, GL_FLOAT, GL_FALSE, sizeof(Simple2DVertex), (GLvoid *)offsetof(Simple2DVertex, x));
+	_glVertexAttribPointer(colour_position, 2, GL_FLOAT, GL_FALSE, sizeof(Simple2DVertex), (GLvoid *)offsetof(Simple2DVertex, u));
 	_glBindVertexArray(0);
 
 	glClearColor(0.0f, 0.0f, 0.0f, 1.0f);