gtk2/gdk/gdkgl.c
Chun-wei Fan cf0175ffce OpenGL/ES: Fix 'R' and 'B' bits inverted on Windows
We need to use GL_BGRA instead of GL_RGBA when doing glReadPixels() on
EGL on Windows (ANGLE) so that the red and blue bits won't be displayed
inverted.

Also fix the logic where we determine whether to bit blit or redraw
everything.
2020-07-30 14:30:13 +08:00

489 lines
16 KiB
C

/* GDK - The GIMP Drawing Kit
* Copyright (C) 2014 Red Hat, Inc.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library. If not, see <http://www.gnu.org/licenses/>.
*/
#include "config.h"
#include "gdkcairo.h"
#include "gdkglcontextprivate.h"
#include "gdkinternals.h"
#include <epoxy/gl.h>
#include <math.h>
#include <string.h>
static const char *
get_vertex_type_name (int type)
{
switch (type)
{
case GL_VERTEX_SHADER:
return "vertex";
case GL_GEOMETRY_SHADER:
return "geometry";
case GL_FRAGMENT_SHADER:
return "fragment";
default:
return "unknown";
}
}
static guint
create_shader (int type,
const char *code)
{
guint shader;
int status;
shader = glCreateShader (type);
glShaderSource (shader, 1, &code, NULL);
glCompileShader (shader);
glGetShaderiv (shader, GL_COMPILE_STATUS, &status);
if (status == GL_FALSE)
{
int log_len;
char *buffer;
glGetShaderiv (shader, GL_INFO_LOG_LENGTH, &log_len);
buffer = g_malloc (log_len + 1);
glGetShaderInfoLog (shader, log_len, NULL, buffer);
g_warning ("Compile failure in %s shader:\n%s", get_vertex_type_name (type), buffer);
g_free (buffer);
glDeleteShader (shader);
return 0;
}
return shader;
}
static void
make_program (GdkGLContextProgram *program,
const char *vertex_shader_path,
const char *fragment_shader_path)
{
guint vertex_shader, fragment_shader;
GBytes *source;
int status;
source = g_resources_lookup_data (vertex_shader_path, 0, NULL);
g_assert (source != NULL);
vertex_shader = create_shader (GL_VERTEX_SHADER, g_bytes_get_data (source, NULL));
g_bytes_unref (source);
if (vertex_shader == 0)
return;
source = g_resources_lookup_data (fragment_shader_path, 0, NULL);
g_assert (source != NULL);
fragment_shader = create_shader (GL_FRAGMENT_SHADER, g_bytes_get_data (source, NULL));
g_bytes_unref (source);
if (fragment_shader == 0)
{
glDeleteShader (vertex_shader);
return;
}
program->program = glCreateProgram ();
glAttachShader (program->program, vertex_shader);
glAttachShader (program->program, fragment_shader);
glLinkProgram (program->program);
glDeleteShader (vertex_shader);
glDeleteShader (fragment_shader);
glGetProgramiv (program->program, GL_LINK_STATUS, &status);
if (status == GL_FALSE)
{
int log_len;
char *buffer;
glGetProgramiv (program->program, GL_INFO_LOG_LENGTH, &log_len);
buffer = g_malloc (log_len + 1);
glGetProgramInfoLog (program->program, log_len, NULL, buffer);
g_warning ("Linker failure: %s\n", buffer);
g_free (buffer);
glDeleteProgram (program->program);
}
program->position_location = glGetAttribLocation (program->program, "position");
program->uv_location = glGetAttribLocation (program->program, "uv");
program->map_location = glGetUniformLocation (program->program, "map");
program->flip_location = glGetUniformLocation (program->program, "flipColors");
}
static void
bind_vao (GdkGLContextPaintData *paint_data)
{
if (paint_data->vertex_array_object == 0)
{
glGenVertexArrays (1, &paint_data->vertex_array_object);
/* ATM we only use one VAO, so always bind it */
glBindVertexArray (paint_data->vertex_array_object);
}
}
static void
use_texture_gles_program (GdkGLContextPaintData *paint_data)
{
if (paint_data->texture_2d_quad_program.program == 0)
make_program (&paint_data->texture_2d_quad_program,
"/org/gtk/libgdk/glsl/gles2-texture.vs.glsl",
"/org/gtk/libgdk/glsl/gles2-texture.fs.glsl");
if (paint_data->current_program != &paint_data->texture_2d_quad_program)
{
paint_data->current_program = &paint_data->texture_2d_quad_program;
glUseProgram (paint_data->current_program->program);
}
}
static void
use_texture_2d_program (GdkGLContextPaintData *paint_data)
{
const char *vertex_shader_path = paint_data->is_legacy
? "/org/gtk/libgdk/glsl/gl2-texture-2d.vs.glsl"
: "/org/gtk/libgdk/glsl/gl3-texture-2d.vs.glsl";
const char *fragment_shader_path = paint_data->is_legacy
? "/org/gtk/libgdk/glsl/gl2-texture-2d.fs.glsl"
: "/org/gtk/libgdk/glsl/gl3-texture-2d.fs.glsl";
if (paint_data->texture_2d_quad_program.program == 0)
make_program (&paint_data->texture_2d_quad_program, vertex_shader_path, fragment_shader_path);
if (paint_data->current_program != &paint_data->texture_2d_quad_program)
{
paint_data->current_program = &paint_data->texture_2d_quad_program;
glUseProgram (paint_data->current_program->program);
}
}
static void
use_texture_rect_program (GdkGLContextPaintData *paint_data)
{
const char *vertex_shader_path = paint_data->is_legacy
? "/org/gtk/libgdk/glsl/gl2-texture-rect.vs.glsl"
: "/org/gtk/libgdk/glsl/gl3-texture-rect.vs.glsl";
const char *fragment_shader_path = paint_data->is_legacy
? "/org/gtk/libgdk/glsl/gl2-texture-rect.fs.glsl"
: "/org/gtk/libgdk/glsl/gl3-texture-rect.vs.glsl";
if (paint_data->texture_rect_quad_program.program == 0)
make_program (&paint_data->texture_rect_quad_program, vertex_shader_path, fragment_shader_path);
if (paint_data->current_program != &paint_data->texture_rect_quad_program)
{
paint_data->current_program = &paint_data->texture_rect_quad_program;
glUseProgram (paint_data->current_program->program);
}
}
void
gdk_gl_texture_quads (GdkGLContext *paint_context,
guint texture_target,
int n_quads,
GdkTexturedQuad *quads,
gboolean flip_colors)
{
GdkGLContextPaintData *paint_data = gdk_gl_context_get_paint_data (paint_context);
GdkGLContextProgram *program;
GdkSurface *surface = gdk_gl_context_get_surface (paint_context);
int surface_scale = gdk_surface_get_scale_factor (surface);
float w = gdk_surface_get_width (surface) * surface_scale;
float h = gdk_surface_get_height (surface) * surface_scale;
int i;
float *vertex_buffer_data;
bind_vao (paint_data);
if (paint_data->tmp_vertex_buffer == 0)
glGenBuffers(1, &paint_data->tmp_vertex_buffer);
if (paint_data->use_es)
use_texture_gles_program (paint_data);
else
{
if (texture_target == GL_TEXTURE_RECTANGLE_ARB)
use_texture_rect_program (paint_data);
else
use_texture_2d_program (paint_data);
}
program = paint_data->current_program;
/* Use texture unit 0 */
glActiveTexture (GL_TEXTURE0);
glUniform1i(program->map_location, 0);
/* Flip 'R' and 'B' colors on GLES, if necessary */
if (gdk_gl_context_get_use_es (paint_context))
glUniform1i (program->flip_location, flip_colors ? 1 : 0);
glEnableVertexAttribArray (program->position_location);
glEnableVertexAttribArray (program->uv_location);
glBindBuffer (GL_ARRAY_BUFFER, paint_data->tmp_vertex_buffer);
glVertexAttribPointer (program->position_location, 2, GL_FLOAT, GL_FALSE, sizeof(float) * 4, NULL);
glVertexAttribPointer (program->uv_location, 2, GL_FLOAT, GL_FALSE, sizeof(float) * 4, (void *) (sizeof(float) * 2));
#define VERTEX_SIZE 4
#define QUAD_N_VERTICES 6
#define QUAD_SIZE (VERTEX_SIZE * QUAD_N_VERTICES)
vertex_buffer_data = g_new (float, n_quads * QUAD_SIZE);
for (i = 0; i < n_quads; i++)
{
GdkTexturedQuad *quad = &quads[i];
float vertex_data[] = {
(quad->x1 * 2) / w - 1, (quad->y1 * 2) / h - 1, quad->u1, quad->v1,
(quad->x1 * 2) / w - 1, (quad->y2 * 2) / h - 1, quad->u1, quad->v2,
(quad->x2 * 2) / w - 1, (quad->y1 * 2) / h - 1, quad->u2, quad->v1,
(quad->x2 * 2) / w - 1, (quad->y2 * 2) / h - 1, quad->u2, quad->v2,
(quad->x1 * 2) / w - 1, (quad->y2 * 2) / h - 1, quad->u1, quad->v2,
(quad->x2 * 2) / w - 1, (quad->y1 * 2) / h - 1, quad->u2, quad->v1,
};
float *vertex = &vertex_buffer_data[i * QUAD_SIZE];
memcpy (vertex, vertex_data, sizeof(vertex_data));
}
glBufferData (GL_ARRAY_BUFFER, sizeof(float) * n_quads * QUAD_SIZE, vertex_buffer_data, GL_STREAM_DRAW);
glDrawArrays (GL_TRIANGLES, 0, n_quads * QUAD_N_VERTICES);
g_free (vertex_buffer_data);
glDisableVertexAttribArray (program->position_location);
glDisableVertexAttribArray (program->uv_location);
}
/* x,y,width,height describes a rectangle in the gl render buffer
coordinate space, and its top left corner is drawn at the current
position according to the cairo translation. */
/**
* gdk_cairo_draw_from_gl:
* @cr: a cairo context
* @surface: The surface we're rendering for (not necessarily into)
* @source: The GL ID of the source buffer
* @source_type: The type of the @source
* @buffer_scale: The scale-factor that the @source buffer is allocated for
* @x: The source x position in @source to start copying from in GL coordinates
* @y: The source y position in @source to start copying from in GL coordinates
* @width: The width of the region to draw
* @height: The height of the region to draw
*
* This is the main way to draw GL content in GTK. It takes a render buffer ID
* (@source_type == #GL_RENDERBUFFER) or a texture id (@source_type == #GL_TEXTURE)
* and draws it onto @cr with an OVER operation, respecting the current clip.
* The top left corner of the rectangle specified by @x, @y, @width and @height
* will be drawn at the current (0,0) position of the cairo_t.
*
* This will work for *all* cairo_t, as long as @surface is realized, but the
* fallback implementation that reads back the pixels from the buffer may be
* used in the general case. In the case of direct drawing to a surface with
* no special effects applied to @cr it will however use a more efficient
* approach.
*
* For #GL_RENDERBUFFER the code will always fall back to software for buffers
* with alpha components, so make sure you use #GL_TEXTURE if using alpha.
*
* Calling this may change the current GL context.
*/
void
gdk_cairo_draw_from_gl (cairo_t *cr,
GdkSurface *surface,
int source,
int source_type,
int buffer_scale,
int x,
int y,
int width,
int height)
{
GdkGLContext *paint_context;
cairo_surface_t *image;
cairo_matrix_t matrix;
guint framebuffer;
int alpha_size = 0;
cairo_region_t *clip_region;
GdkGLContextPaintData *paint_data;
int major, minor, version;
gboolean es_use_bgra = FALSE;
paint_context = gdk_surface_get_paint_gl_context (surface, NULL);
if (paint_context == NULL)
{
g_warning ("gdk_cairo_draw_gl_render_buffer failed - no paint context");
return;
}
clip_region = gdk_cairo_region_from_clip (cr);
es_use_bgra = gdk_gl_context_use_es_bgra (paint_context);
gdk_gl_context_make_current (paint_context);
paint_data = gdk_gl_context_get_paint_data (paint_context);
if (paint_data->tmp_framebuffer == 0)
glGenFramebuffers (1, &paint_data->tmp_framebuffer);
if (source_type == GL_RENDERBUFFER)
{
glBindRenderbuffer (GL_RENDERBUFFER, source);
glGetRenderbufferParameteriv (GL_RENDERBUFFER, GL_RENDERBUFFER_ALPHA_SIZE, &alpha_size);
}
else if (source_type == GL_TEXTURE)
{
glBindTexture (GL_TEXTURE_2D, source);
if (gdk_gl_context_get_use_es (paint_context))
alpha_size = 1;
else
glGetTexLevelParameteriv (GL_TEXTURE_2D, 0, GL_TEXTURE_ALPHA_SIZE, &alpha_size);
}
else
{
g_warning ("Unsupported gl source type %d\n", source_type);
return;
}
cairo_get_matrix (cr, &matrix);
gdk_gl_context_get_version (paint_context, &major, &minor);
version = major * 100 + minor;
/* TODO: Use glTexSubImage2D() and do a row-by-row copy to replace
* the GL_UNPACK_ROW_LENGTH support
*/
if (gdk_gl_context_get_use_es (paint_context) &&
!(version >= 300 || gdk_gl_context_has_unpack_subimage (paint_context)))
goto out;
/* TODO: avoid reading back non-required data due to dest clip */
image = cairo_surface_create_similar_image (cairo_get_target (cr),
(alpha_size == 0) ? CAIRO_FORMAT_RGB24 : CAIRO_FORMAT_ARGB32,
width, height);
cairo_surface_set_device_scale (image, buffer_scale, buffer_scale);
framebuffer = paint_data->tmp_framebuffer;
glBindFramebuffer (GL_FRAMEBUFFER, framebuffer);
if (source_type == GL_RENDERBUFFER)
{
/* Create a framebuffer with the source renderbuffer and
make it the current target for reads */
glFramebufferRenderbuffer (GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0,
GL_RENDERBUFFER, source);
}
else
{
glFramebufferTexture2D (GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0,
GL_TEXTURE_2D, source, 0);
}
glPixelStorei (GL_PACK_ALIGNMENT, 4);
glPixelStorei (GL_PACK_ROW_LENGTH, cairo_image_surface_get_stride (image) / 4);
/* The implicit format conversion is going to make this path slower */
if (!gdk_gl_context_get_use_es (paint_context))
glReadPixels (x, y, width, height, GL_BGRA, GL_UNSIGNED_INT_8_8_8_8_REV,
cairo_image_surface_get_data (image));
else
glReadPixels (x, y, width, height, es_use_bgra ? GL_BGRA : GL_RGBA, GL_UNSIGNED_BYTE,
cairo_image_surface_get_data (image));
glPixelStorei (GL_PACK_ROW_LENGTH, 0);
glBindFramebuffer (GL_FRAMEBUFFER, 0);
cairo_surface_mark_dirty (image);
/* Invert due to opengl having different origin */
cairo_scale (cr, 1, -1);
cairo_translate (cr, 0, -height / buffer_scale);
cairo_set_source_surface (cr, image, 0, 0);
cairo_set_operator (cr, CAIRO_OPERATOR_OVER);
cairo_paint (cr);
cairo_surface_destroy (image);
out:
if (clip_region)
cairo_region_destroy (clip_region);
}
/**
* gdk_cairo_surface_upload_to_gl:
* @surface: a Cairo surface
* @target: a GL texture target
* @width: the width of the texture @target
* @height: the height of the texture @target
* @context: (nullable): a #GdkGLContext, or %NULL to use the currently
* bound context
*
* Uploads the contents of a Cairo @surface to a GL texture @target.
*/
void
gdk_cairo_surface_upload_to_gl (cairo_surface_t *surface,
int target,
int width,
int height,
GdkGLContext *context)
{
cairo_rectangle_int_t rect;
cairo_surface_t *tmp;
double device_x_offset, device_y_offset;
g_return_if_fail (surface != NULL);
g_return_if_fail (context == NULL || GDK_IS_GL_CONTEXT (context));
if (context == NULL)
context = gdk_gl_context_get_current ();
cairo_surface_flush (surface);
cairo_surface_get_device_offset (surface, &device_x_offset, &device_y_offset);
rect.x = (int) device_x_offset;
rect.y = (int) device_y_offset;
rect.width = width;
rect.height = height;
tmp = cairo_surface_map_to_image (surface, &rect);
gdk_gl_context_upload_texture (context,
cairo_image_surface_get_data (tmp),
rect.width,
rect.height,
cairo_image_surface_get_stride (tmp),
target);
cairo_surface_unmap_image (surface, tmp);
}