shithub: cstory

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Move away from Legacy OpenGL shader variables

--- a/src/Backends/Rendering/OpenGL2.cpp

+++ b/src/Backends/Rendering/OpenGL2.cpp

@@ -33,8 +33,8 @@

 static GLuint program_colour_fill;

 static GLuint program_glyph;

-static GLint uniform_colour_fill_colour;

-static GLint uniform_glyph_colour;

+static GLint program_colour_fill_uniform_colour;

+static GLint program_glyph_uniform_colour;

 static GLuint framebuffer_id;

 static GLfloat vertex_buffer[4][2];

@@ -44,18 +44,22 @@

 static const GLchar *vertex_shader_plain = " \

 #version 120\n \

+attribute vec2 input_vertex_coordinates; \

 void main() \

 { \

-	gl_Position = gl_Vertex; \

+	gl_Position = vec4(input_vertex_coordinates.x, input_vertex_coordinates.y, 0.0, 1.0); \

 } \

 ";

 static const GLchar *vertex_shader_texture = " \

 #version 120\n \

+attribute vec2 input_vertex_coordinates; \

+attribute vec2 input_texture_coordinates; \

+varying vec2 texture_coordinates; \

 void main() \

 { \

-	gl_TexCoord[0] = gl_MultiTexCoord0; \

-	gl_Position = gl_Vertex; \

+	texture_coordinates = input_texture_coordinates; \

+	gl_Position = vec4(input_vertex_coordinates.x, input_vertex_coordinates.y, 0.0, 1.0); \

 } \

 ";

@@ -62,9 +66,10 @@

 static const GLchar *fragment_shader_texture = " \

 #version 120\n \

 uniform sampler2D tex; \

+varying vec2 texture_coordinates; \

 void main() \

 { \

-	gl_FragColor = texture2D(tex, gl_TexCoord[0].st); \

+	gl_FragColor = texture2D(tex, texture_coordinates); \

 } \

 ";

@@ -71,9 +76,10 @@

 static const GLchar *fragment_shader_texture_colour_key = " \

 #version 120\n \

 uniform sampler2D tex; \

+varying vec2 texture_coordinates; \

 void main() \

 { \

-	vec4 colour = texture2D(tex, gl_TexCoord[0].st); \

+	vec4 colour = texture2D(tex, texture_coordinates); \

 \

 	if (colour.xyz == vec3(0.0f, 0.0f, 0.0f)) \

 		discard; \

@@ -95,9 +101,10 @@

 #version 120\n \

 uniform sampler2D tex; \

 uniform vec4 colour; \

+varying vec2 texture_coordinates; \

 void main() \

 { \

-	gl_FragColor = colour * texture2D(tex, gl_TexCoord[0].st); \

+	gl_FragColor = colour * texture2D(tex, texture_coordinates); \

 } \

 ";

@@ -127,6 +134,9 @@

 	glAttachShader(program_id, fragment_shader);

+	glBindAttribLocation(program_id, 1, "input_vertex_coordinates");

+	glBindAttribLocation(program_id, 2, "input_texture_coordinates");

+

 	glLinkProgram(program_id);

 	glGetProgramiv(program_id, GL_LINK_STATUS, &shader_status);

@@ -168,10 +178,6 @@

 	glEnable(GL_BLEND);

 	glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);

-	glEnableClientState(GL_VERTEX_ARRAY);

-	glVertexPointer(2, GL_FLOAT, 0, vertex_buffer);

-	glTexCoordPointer(2, GL_FLOAT, 0, texture_coordinate_buffer);

-

 	glClearColor(0.0f, 0.0f, 0.0f, 1.0f);

 	glClear(GL_COLOR_BUFFER_BIT);

@@ -185,9 +191,13 @@

 		printf("Failed to compile shaders\n");

 	// Get shader uniforms

-	uniform_colour_fill_colour = glGetUniformLocation(program_colour_fill, "colour");

-	uniform_glyph_colour = glGetUniformLocation(program_glyph, "colour");

+	program_colour_fill_uniform_colour = glGetUniformLocation(program_colour_fill, "colour");

+	program_glyph_uniform_colour = glGetUniformLocation(program_glyph, "colour");

+	glEnableVertexAttribArray(1);

+	glVertexAttribPointer(1, 2, GL_FLOAT, GL_FALSE, 0, vertex_buffer);

+	glVertexAttribPointer(2, 2, GL_FLOAT, GL_FALSE, 0, texture_coordinate_buffer);

+

 	// Set up framebuffer (used for surface-to-surface blitting)

 	glGenFramebuffersEXT(1, &framebuffer_id);

 	glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, framebuffer_id);

@@ -220,7 +230,8 @@

 {

 	glUseProgram(program_texture);

-	glEnableClientState(GL_TEXTURE_COORD_ARRAY);

+	// Enable texture coordinates, since this uses textures

+	glEnableVertexAttribArray(2);

 	// Target actual screen, and not our framebuffer

 	glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, 0);

@@ -316,7 +327,8 @@

 	// Switch to colour-key shader if we have to

 	glUseProgram(colour_key ? program_texture_colour_key : program_texture);

-	glEnableClientState(GL_TEXTURE_COORD_ARRAY);

+	// Enable texture coordinates, since this uses textures

+	glEnableVertexAttribArray(2);

 	glBindTexture(GL_TEXTURE_2D, source_surface->texture_id);

@@ -382,9 +394,10 @@

 	glUseProgram(program_colour_fill);

-	glDisableClientState(GL_TEXTURE_COORD_ARRAY);

+	// Disable texture coordinate array, since this doesn't use textures

+	glDisableVertexAttribArray(2);

-	glUniform4f(uniform_colour_fill_colour, red / 255.0f, green / 255.0f, blue / 255.0f, 1.0f);

+	glUniform4f(program_colour_fill_uniform_colour, red / 255.0f, green / 255.0f, blue / 255.0f, 1.0f);

 	const GLfloat vertex_left = (rect->left * (2.0f / surface->width)) - 1.0f;

 	const GLfloat vertex_right = (rect->right * (2.0f / surface->width)) - 1.0f;

@@ -520,7 +533,8 @@

 {

 	glUseProgram(program_glyph);

-	glEnableClientState(GL_TEXTURE_COORD_ARRAY);

+	// Enable texture coordinates, since this uses textures

+	glEnableVertexAttribArray(2);

 	glBindTexture(GL_TEXTURE_2D, glyph->texture_id);

@@ -529,7 +543,7 @@

 	const GLfloat vertex_top = (y * (2.0f / surface->height)) - 1.0f;

 	const GLfloat vertex_bottom = ((y + glyph->height) * (2.0f / surface->height)) - 1.0f;

-	glUniform4f(uniform_glyph_colour, colours[0] / 255.0f, colours[1] / 255.0f, colours[2] / 255.0f, 1.0f);

+	glUniform4f(program_glyph_uniform_colour, colours[0] / 255.0f, colours[1] / 255.0f, colours[2] / 255.0f, 1.0f);

 	texture_coordinate_buffer[0][0] = 0.0f;

 	texture_coordinate_buffer[0][1] = 0.0f;