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gdk_gl_texture_quad: Use shaders to texture things
This is the modern way OpenGL works, and using it will let us switch to a core context for the paint context, and work on OpenGL ES 2.0.
This commit is contained in:
Alexander Larsson
parent
c78e7e7f17
commit
e417b18373
196
gdk/gdkgl.c
196
gdk/gdkgl.c
@ -35,25 +35,193 @@ gdk_cairo_surface_mark_as_direct (cairo_surface_t *surface,
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g_object_ref (window), g_object_unref);
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}
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static const char *
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get_vertex_type_name (int type)
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{
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switch (type)
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{
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case GL_VERTEX_SHADER:
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return "vertex";
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case GL_GEOMETRY_SHADER:
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return "geometry";
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case GL_FRAGMENT_SHADER:
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return "fragment";
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}
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return "unknown";
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}
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guint
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create_shader (int type, const char const *code)
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{
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guint shader;
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int status;
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shader = glCreateShader (type);
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glShaderSource (shader, 1, &code, NULL);
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glCompileShader (shader);
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glGetShaderiv (shader, GL_COMPILE_STATUS, &status);
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if (status == GL_FALSE)
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{
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int log_len;
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char *buffer;
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glGetShaderiv (shader, GL_INFO_LOG_LENGTH, &log_len);
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buffer = g_malloc (log_len + 1);
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glGetShaderInfoLog (shader, log_len, NULL, buffer);
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g_warning ("Compile failure in %s shader:\n%s\n", get_vertex_type_name (type), buffer);
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g_free (buffer);
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glDeleteShader (shader);
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return 0;
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}
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return shader;
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}
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guint
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make_program (const char const *vertex_shader_code, const char const *fragment_shader_code)
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{
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guint program, vertex_shader, fragment_shader;
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int status;
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vertex_shader = create_shader (GL_VERTEX_SHADER, vertex_shader_code);
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if (vertex_shader == 0)
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return 0;
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fragment_shader = create_shader (GL_FRAGMENT_SHADER, fragment_shader_code);
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if (fragment_shader == 0)
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{
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glDeleteShader (vertex_shader);
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return 0;
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}
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program = glCreateProgram ();
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glAttachShader (program, vertex_shader);
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glAttachShader (program, fragment_shader);
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glLinkProgram (program);
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glDeleteShader (vertex_shader);
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glDeleteShader (fragment_shader);
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glGetProgramiv (program, GL_LINK_STATUS, &status);
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if (status == GL_FALSE)
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{
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int log_len;
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char *buffer;
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glGetProgramiv (program, GL_INFO_LOG_LENGTH, &log_len);
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buffer = g_malloc (log_len + 1);
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glGetProgramInfoLog (program, log_len, NULL, buffer);
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g_warning ("Linker failure: %s\n", buffer);
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g_free (buffer);
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glDeleteProgram (program);
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return 0;
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}
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return program;
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}
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static void
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bind_vao (GdkGLContextPaintData *paint_data)
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{
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if (paint_data->vertex_array_object == 0)
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{
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glGenVertexArrays (1, &paint_data->vertex_array_object);
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/* ATM we only use one VAO, so always bind it */
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glBindVertexArray (paint_data->vertex_array_object);
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}
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}
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static void
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use_texture_program (GdkGLContextPaintData *paint_data)
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{
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const char *vertex_shader_code =
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"#version 120\n"
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"uniform sampler2D map;"
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"attribute vec2 position;\n"
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"attribute vec2 uv;\n"
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"varying vec2 vUv;\n"
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"void main() {\n"
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" gl_Position = vec4(position, 0, 1);\n"
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" vUv = uv;\n"
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"}\n";
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const char *fragment_shader_code =
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"#version 120\n"
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"varying vec2 vUv;\n"
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"uniform sampler2D map;\n"
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"void main() {\n"
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" gl_FragColor = texture2D (map, vUv);\n"
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"}\n";
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if (paint_data->texture_quad_program == 0)
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{
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paint_data->texture_quad_program = make_program (vertex_shader_code, fragment_shader_code);
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paint_data->texture_quad_program_position_location = glGetAttribLocation (paint_data->texture_quad_program, "position");
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paint_data->texture_quad_program_uv_location = glGetAttribLocation (paint_data->texture_quad_program, "uv");
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}
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if (paint_data->current_program != paint_data->texture_quad_program)
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{
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glUseProgram (paint_data->texture_quad_program);
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paint_data->current_program = paint_data->texture_quad_program;
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}
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}
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void
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gdk_gl_texture_quad (float x1, float y1,
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gdk_gl_texture_quad (GdkGLContext *paint_context,
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float x1, float y1,
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float x2, float y2,
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float u1, float v1,
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float u2, float v2)
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{
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glBegin (GL_QUADS);
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glTexCoord2f (u1, v2);
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glVertex2f (x1, y2);
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GdkGLContextPaintData *paint_data = gdk_gl_context_get_paint_data (paint_context);;
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GdkWindow *window = gdk_gl_context_get_window (paint_context);
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float w = gdk_window_get_width (window);
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float h = gdk_window_get_height (window);
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float vertex_buffer_data[] = {
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(x2 * 2) / w - 1, (y1 * 2) / h - 1,
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(x2 * 2) / w - 1, (y2 * 2) / h - 1,
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(x1 * 2) / w - 1, (y2 * 2) / h - 1,
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(x1 * 2) / w - 1, (y1 * 2) / h - 1,
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};
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float uv_buffer_data[] = {
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u2, v1,
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u2, v2,
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u1, v2,
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u1, v1,
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};
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glTexCoord2f (u2, v2);
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glVertex2f (x2, y2);
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bind_vao (paint_data);
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glTexCoord2f (u2, v1);
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glVertex2f (x2, y1);
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if (paint_data->tmp_vertex_buffer == 0)
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glGenBuffers(1, &paint_data->tmp_vertex_buffer);
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glTexCoord2f (u1, v1);
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glVertex2f (x1, y1);
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glEnd();
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if (paint_data->tmp_uv_buffer == 0)
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glGenBuffers(1, &paint_data->tmp_uv_buffer);
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use_texture_program (paint_data);
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glActiveTexture (GL_TEXTURE0);
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glEnableVertexAttribArray (0);
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glBindBuffer (GL_ARRAY_BUFFER, paint_data->tmp_vertex_buffer);
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glBufferData (GL_ARRAY_BUFFER, sizeof(vertex_buffer_data), vertex_buffer_data, GL_STREAM_DRAW);
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glVertexAttribPointer (paint_data->texture_quad_program_position_location,
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2, GL_FLOAT, GL_FALSE, 0, NULL);
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glEnableVertexAttribArray (1);
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glBindBuffer (GL_ARRAY_BUFFER, paint_data->tmp_uv_buffer);
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glBufferData (GL_ARRAY_BUFFER, sizeof(uv_buffer_data), uv_buffer_data, GL_STREAM_DRAW);
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glVertexAttribPointer (paint_data->texture_quad_program_uv_location,
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2, GL_FLOAT, GL_FALSE, 0, NULL);
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glDrawArrays (GL_TRIANGLE_FAN, 0, 4);
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glDisableVertexAttribArray (0);
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glDisableVertexAttribArray (1);
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}
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@ -328,7 +496,8 @@ gdk_cairo_draw_from_gl (cairo_t *cr,
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int clipped_src_x = x + (dest.x - dx * window_scale);
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int clipped_src_y = y + (height - dest.height - (dest.y - dy * window_scale));
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gdk_gl_texture_quad (dest.x, FLIP_Y(dest.y),
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gdk_gl_texture_quad (paint_context,
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dest.x, FLIP_Y(dest.y),
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dest.x + dest.width, FLIP_Y(dest.y + dest.height),
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clipped_src_x / (float)texture_width, (clipped_src_y + dest.height) / (float)texture_height,
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(clipped_src_x + dest.width) / (float)texture_width, clipped_src_y / (float)texture_height);
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@ -507,7 +676,8 @@ gdk_gl_texture_from_surface (cairo_surface_t *surface,
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vmax = 1.0;
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}
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gdk_gl_texture_quad (rect.x * window_scale, FLIP_Y(rect.y) * window_scale,
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gdk_gl_texture_quad (paint_context,
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rect.x * window_scale, FLIP_Y(rect.y) * window_scale,
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(rect.x + rect.width) * window_scale, FLIP_Y(rect.y + rect.height) * window_scale,
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0, 0,
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umax, vmax);
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@ -57,7 +57,14 @@ void gdk_gl_context_end_frame (GdkGLContext *context,
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typedef struct {
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guint vertex_array_object;
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guint tmp_framebuffer;
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guint tmp_vertex_buffer;
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guint tmp_uv_buffer;
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guint current_program;
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guint texture_quad_program;
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guint texture_quad_program_position_location;
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guint texture_quad_program_uv_location;
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} GdkGLContextPaintData;
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GdkGLContextPaintData *gdk_gl_context_get_paint_data (GdkGLContext *context);
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@ -341,7 +341,8 @@ gboolean _gdk_cairo_surface_extents (cairo_surface_t *surface,
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GdkRectangle *extents);
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void gdk_gl_texture_from_surface (cairo_surface_t *surface,
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cairo_region_t *region);
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void gdk_gl_texture_quad (float x1, float y1,
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void gdk_gl_texture_quad (GdkGLContext *paint_context,
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float x1, float y1,
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float x2, float y2,
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float u1, float v1,
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float u2, float v2);
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@ -466,7 +466,8 @@ gdk_x11_gl_context_texture_from_surface (GdkGLContext *paint_context,
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vscale = 1.0 / cairo_xlib_surface_get_height (surface);
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}
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gdk_gl_texture_quad (rect.x * window_scale, FLIP_Y(rect.y) * window_scale,
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gdk_gl_texture_quad (paint_context,
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rect.x * window_scale, FLIP_Y(rect.y) * window_scale,
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(rect.x + rect.width) * window_scale, FLIP_Y(rect.y + rect.height) * window_scale,
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uscale * src_x, vscale * src_y,
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uscale * (src_x + src_width), vscale * (src_y + src_height));
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