gtk/gdk/gdkgl.c
Chun-wei Fan 9fd9f61b00 gdkgl: Use vfunc For Uploading Textures
As the alignments, strides and image formats may be different across
platforms, make the texture upload a vfunc to allow backends to override
the GL commands for uploading textures for the software implementation for
gdk_gl_texture_from_surface(), if necessary.

Suggested by Alex to avoid copying non-trivial portions of code which would
then add maintainenace burden.

https://bugzilla.gnome.org/show_bug.cgi?id=740795
2014-12-17 16:06:25 +08:00

758 lines
25 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 cairo_user_data_key_t direct_key;
void
gdk_cairo_surface_mark_as_direct (cairo_surface_t *surface,
GdkWindow *window)
{
cairo_surface_set_user_data (surface, &direct_key,
g_object_ref (window), g_object_unref);
}
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";
}
return "unknown";
}
static guint
create_shader (int type, const char const *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\n", get_vertex_type_name (type), buffer);
g_free (buffer);
glDeleteShader (shader);
return 0;
}
return shader;
}
static void
make_program (GdkGLContextProgram *program,
const char const *vertex_shader_code,
const char const *fragment_shader_code)
{
guint vertex_shader, fragment_shader;
int status;
vertex_shader = create_shader (GL_VERTEX_SHADER, vertex_shader_code);
if (vertex_shader == 0)
return;
fragment_shader = create_shader (GL_FRAGMENT_SHADER, fragment_shader_code);
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");
}
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_2d_program (GdkGLContextPaintData *paint_data)
{
const char *vertex_shader_code =
"#version 120\n"
"uniform sampler2D map;"
"attribute vec2 position;\n"
"attribute vec2 uv;\n"
"varying vec2 vUv;\n"
"void main() {\n"
" gl_Position = vec4(position, 0, 1);\n"
" vUv = uv;\n"
"}\n";
const char *fragment_shader_code =
"#version 120\n"
"varying vec2 vUv;\n"
"uniform sampler2D map;\n"
"void main() {\n"
" gl_FragColor = texture2D (map, vUv);\n"
"}\n";
if (paint_data->texture_2d_quad_program.program == 0)
make_program (&paint_data->texture_2d_quad_program, vertex_shader_code, fragment_shader_code);
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_code =
"#version 120\n"
"uniform sampler2DRect map;"
"attribute vec2 position;\n"
"attribute vec2 uv;\n"
"varying vec2 vUv;\n"
"void main() {\n"
" gl_Position = vec4(position, 0, 1);\n"
" vUv = uv;\n"
"}\n";
const char *fragment_shader_code =
"#version 120\n"
"varying vec2 vUv;\n"
"uniform sampler2DRect map;\n"
"void main() {\n"
" gl_FragColor = texture2DRect (map, vUv);\n"
"}\n";
if (paint_data->texture_rect_quad_program.program == 0)
make_program (&paint_data->texture_rect_quad_program, vertex_shader_code, fragment_shader_code);
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)
{
GdkGLContextPaintData *paint_data = gdk_gl_context_get_paint_data (paint_context);
GdkGLContextProgram *program;
GdkWindow *window = gdk_gl_context_get_window (paint_context);
int window_scale = gdk_window_get_scale_factor (window);
float w = gdk_window_get_width (window) * window_scale;
float h = gdk_window_get_height (window) * window_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 (texture_target == GL_TEXTURE_RECTANGLE_ARB)
use_texture_rect_program (paint_data);
else
use_texture_2d_program (paint_data);
program = paint_data->current_program;
glActiveTexture (GL_TEXTURE0);
glUniform1i(program->map_location, 0); /* Use texture unit 0 */
glEnableVertexAttribArray (0);
glEnableVertexAttribArray (1);
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 (0);
glDisableVertexAttribArray (1);
}
/* 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
* @window: The window 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 @window 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 window 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.
*
* Since: 3.16
*/
void
gdk_cairo_draw_from_gl (cairo_t *cr,
GdkWindow *window,
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;
int dx, dy, window_scale;
gboolean trivial_transform;
cairo_surface_t *group_target;
GdkWindow *direct_window, *impl_window;
guint framebuffer;
int alpha_size = 0;
cairo_region_t *clip_region;
GdkGLContextPaintData *paint_data;
impl_window = window->impl_window;
window_scale = gdk_window_get_scale_factor (impl_window);
paint_context = gdk_window_get_paint_gl_context (window, 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);
gdk_gl_context_make_current (paint_context);
paint_data = gdk_gl_context_get_paint_data (paint_context);
if (paint_data->tmp_framebuffer == 0)
glGenFramebuffersEXT (1, &paint_data->tmp_framebuffer);
if (source_type == GL_RENDERBUFFER)
{
glBindRenderbufferEXT (GL_RENDERBUFFER_EXT, source);
glGetRenderbufferParameteriv (GL_RENDERBUFFER, GL_RENDERBUFFER_ALPHA_SIZE, &alpha_size);
}
else if (source_type == GL_TEXTURE)
{
glBindTexture (GL_TEXTURE_2D, source);
glGetTexLevelParameteriv (GL_TEXTURE_2D, 0, GL_TEXTURE_ALPHA_SIZE, &alpha_size);
}
else
{
g_warning ("Unsupported gl source type %d\n", source_type);
return;
}
group_target = cairo_get_group_target (cr);
direct_window = cairo_surface_get_user_data (group_target, &direct_key);
cairo_get_matrix (cr, &matrix);
dx = matrix.x0;
dy = matrix.y0;
/* Trivial == integer-only translation */
trivial_transform =
(double)dx == matrix.x0 && (double)dy == matrix.y0 &&
matrix.xx == 1.0 && matrix.xy == 0.0 &&
matrix.yx == 0.0 && matrix.yy == 1.0;
/* For direct paint of non-alpha renderbuffer, we can
just do a bitblit */
if ((_gdk_gl_flags & GDK_GL_SOFTWARE_DRAW_GL) == 0 &&
source_type == GL_RENDERBUFFER &&
alpha_size == 0 &&
direct_window != NULL &&
direct_window->current_paint.use_gl &&
trivial_transform &&
clip_region != NULL)
{
int unscaled_window_height;
int i;
/* Create a framebuffer with the source renderbuffer and
make it the current target for reads */
framebuffer = paint_data->tmp_framebuffer;
glBindFramebufferEXT (GL_FRAMEBUFFER_EXT, framebuffer);
glFramebufferRenderbufferEXT (GL_FRAMEBUFFER_EXT, GL_COLOR_ATTACHMENT0_EXT,
GL_RENDERBUFFER_EXT, source);
glBindFramebufferEXT (GL_DRAW_FRAMEBUFFER_EXT, 0);
/* Translate to impl coords */
cairo_region_translate (clip_region, dx, dy);
glEnable (GL_SCISSOR_TEST);
gdk_window_get_unscaled_size (impl_window, NULL, &unscaled_window_height);
glDrawBuffer (GL_BACK);
#define FLIP_Y(_y) (unscaled_window_height - (_y))
for (i = 0; i < cairo_region_num_rectangles (clip_region); i++)
{
cairo_rectangle_int_t clip_rect, dest;
cairo_region_get_rectangle (clip_region, i, &clip_rect);
clip_rect.x *= window_scale;
clip_rect.y *= window_scale;
clip_rect.width *= window_scale;
clip_rect.height *= window_scale;
glScissor (clip_rect.x, FLIP_Y (clip_rect.y + clip_rect.height),
clip_rect.width, clip_rect.height);
dest.x = dx * window_scale;
dest.y = dy * window_scale;
dest.width = width * window_scale / buffer_scale;
dest.height = height * window_scale / buffer_scale;
if (gdk_rectangle_intersect (&clip_rect, &dest, &dest))
{
int clipped_src_x = x + (dest.x - dx * window_scale);
int clipped_src_y = y + (height - dest.height - (dest.y - dy * window_scale));
glBlitFramebufferEXT(clipped_src_x, clipped_src_y,
(clipped_src_x + dest.width), (clipped_src_y + dest.height),
dest.x, FLIP_Y(dest.y + dest.height),
dest.x + dest.width, FLIP_Y(dest.y),
GL_COLOR_BUFFER_BIT, GL_NEAREST);
if (impl_window->current_paint.flushed_region)
{
cairo_rectangle_int_t flushed_rect;
flushed_rect.x = dest.x / window_scale;
flushed_rect.y = dest.y / window_scale;
flushed_rect.width = (dest.x + dest.width + window_scale - 1) / window_scale - flushed_rect.x;
flushed_rect.height = (dest.y + dest.height + window_scale - 1) / window_scale - flushed_rect.y;
cairo_region_union_rectangle (impl_window->current_paint.flushed_region,
&flushed_rect);
cairo_region_subtract_rectangle (impl_window->current_paint.need_blend_region,
&flushed_rect);
}
}
}
glDisable (GL_SCISSOR_TEST);
glBindFramebufferEXT (GL_FRAMEBUFFER_EXT, 0);
#undef FLIP_Y
}
/* For direct paint of alpha or non-alpha textures we can use texturing */
else if ((_gdk_gl_flags & GDK_GL_SOFTWARE_DRAW_GL) == 0 &&
source_type == GL_TEXTURE &&
direct_window != NULL &&
direct_window->current_paint.use_gl &&
trivial_transform &&
clip_region != NULL)
{
int unscaled_window_height;
GLint texture_width;
GLint texture_height;
int i, n_rects, n_quads;
GdkTexturedQuad *quads;
cairo_rectangle_int_t clip_rect;
/* Translate to impl coords */
cairo_region_translate (clip_region, dx, dy);
if (alpha_size != 0)
{
cairo_region_t *opaque_region, *blend_region;
opaque_region = cairo_region_copy (clip_region);
cairo_region_subtract (opaque_region, impl_window->current_paint.flushed_region);
cairo_region_subtract (opaque_region, impl_window->current_paint.need_blend_region);
if (!cairo_region_is_empty (opaque_region))
gdk_gl_texture_from_surface (impl_window->current_paint.surface,
opaque_region);
blend_region = cairo_region_copy (clip_region);
cairo_region_intersect (blend_region, impl_window->current_paint.need_blend_region);
glEnable (GL_BLEND);
if (!cairo_region_is_empty (blend_region))
gdk_gl_texture_from_surface (impl_window->current_paint.surface,
blend_region);
cairo_region_destroy (opaque_region);
cairo_region_destroy (blend_region);
}
glBindTexture (GL_TEXTURE_2D, source);
glGetTexLevelParameteriv (GL_TEXTURE_2D, 0, GL_TEXTURE_WIDTH, &texture_width);
glGetTexLevelParameteriv (GL_TEXTURE_2D, 0, GL_TEXTURE_HEIGHT, &texture_height);
glTexParameteri (GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
glTexParameteri (GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
glTexParameteri (GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
glTexParameteri (GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
glEnable (GL_SCISSOR_TEST);
glEnable (GL_TEXTURE_2D);
gdk_window_get_unscaled_size (impl_window, NULL, &unscaled_window_height);
#define FLIP_Y(_y) (unscaled_window_height - (_y))
cairo_region_get_extents (clip_region, &clip_rect);
glScissor (clip_rect.x * window_scale, FLIP_Y ((clip_rect.y + clip_rect.height) * window_scale),
clip_rect.width * window_scale, clip_rect.height * window_scale);
n_quads = 0;
n_rects = cairo_region_num_rectangles (clip_region);
quads = g_new (GdkTexturedQuad, n_rects);
for (i = 0; i < n_rects; i++)
{
cairo_rectangle_int_t dest;
cairo_region_get_rectangle (clip_region, i, &clip_rect);
clip_rect.x *= window_scale;
clip_rect.y *= window_scale;
clip_rect.width *= window_scale;
clip_rect.height *= window_scale;
dest.x = dx * window_scale;
dest.y = dy * window_scale;
dest.width = width * window_scale / buffer_scale;
dest.height = height * window_scale / buffer_scale;
if (gdk_rectangle_intersect (&clip_rect, &dest, &dest))
{
int clipped_src_x = x + (dest.x - dx * window_scale);
int clipped_src_y = y + (height - dest.height - (dest.y - dy * window_scale));
GdkTexturedQuad quad = {
dest.x, FLIP_Y(dest.y),
dest.x + dest.width, FLIP_Y(dest.y + dest.height),
clipped_src_x / (float)texture_width, (clipped_src_y + dest.height) / (float)texture_height,
(clipped_src_x + dest.width) / (float)texture_width, clipped_src_y / (float)texture_height,
};
quads[n_quads++] = quad;
if (impl_window->current_paint.flushed_region)
{
cairo_rectangle_int_t flushed_rect;
flushed_rect.x = dest.x / window_scale;
flushed_rect.y = dest.y / window_scale;
flushed_rect.width = (dest.x + dest.width + window_scale - 1) / window_scale - flushed_rect.x;
flushed_rect.height = (dest.y + dest.height + window_scale - 1) / window_scale - flushed_rect.y;
cairo_region_union_rectangle (impl_window->current_paint.flushed_region,
&flushed_rect);
cairo_region_subtract_rectangle (impl_window->current_paint.need_blend_region,
&flushed_rect);
}
}
}
if (n_quads > 0)
gdk_gl_texture_quads (paint_context, GL_TEXTURE_2D, n_quads, quads);
g_free (quads);
if (alpha_size != 0)
glDisable (GL_BLEND);
glDisable (GL_TEXTURE_2D);
#undef FLIP_Y
}
else
{
/* Software fallback */
/* 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;
glBindFramebufferEXT (GL_FRAMEBUFFER_EXT, framebuffer);
if (source_type == GL_RENDERBUFFER)
{
/* Create a framebuffer with the source renderbuffer and
make it the current target for reads */
glFramebufferRenderbufferEXT (GL_FRAMEBUFFER_EXT, GL_COLOR_ATTACHMENT0_EXT,
GL_RENDERBUFFER_EXT, source);
}
else
{
glFramebufferTexture2DEXT (GL_FRAMEBUFFER_EXT, GL_COLOR_ATTACHMENT0_EXT,
GL_TEXTURE_2D, source, 0);
}
glPixelStorei (GL_PACK_ALIGNMENT, 4);
glPixelStorei (GL_PACK_ROW_LENGTH, cairo_image_surface_get_stride (image) / 4);
glReadPixels (x, y, width, height, GL_BGRA, GL_UNSIGNED_INT_8_8_8_8_REV,
cairo_image_surface_get_data (image));
glPixelStorei (GL_PACK_ROW_LENGTH, 0);
glBindFramebufferEXT (GL_FRAMEBUFFER_EXT, 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);
}
if (clip_region)
cairo_region_destroy (clip_region);
}
/* This is always called with the paint context current */
void
gdk_gl_texture_from_surface (cairo_surface_t *surface,
cairo_region_t *region)
{
GdkGLContext *paint_context;
cairo_surface_t *image;
double device_x_offset, device_y_offset;
cairo_rectangle_int_t rect, e;
int n_rects, i;
GdkWindow *window;
int unscaled_window_height;
unsigned int texture_id;
int window_scale;
double sx, sy;
float umax, vmax;
gboolean use_texture_rectangle;
guint target;
paint_context = gdk_gl_context_get_current ();
if ((_gdk_gl_flags & GDK_GL_SOFTWARE_DRAW_SURFACE) == 0 &&
paint_context &&
GDK_GL_CONTEXT_GET_CLASS (paint_context)->texture_from_surface &&
GDK_GL_CONTEXT_GET_CLASS (paint_context)->texture_from_surface (paint_context, surface, region))
return;
/* Software fallback */
use_texture_rectangle = gdk_gl_context_use_texture_rectangle (paint_context);
window = gdk_gl_context_get_window (paint_context);
window_scale = gdk_window_get_scale_factor (window);
gdk_window_get_unscaled_size (window, NULL, &unscaled_window_height);
sx = sy = 1;
cairo_surface_get_device_scale (window->current_paint.surface, &sx, &sy);
cairo_surface_get_device_offset (surface,
&device_x_offset, &device_y_offset);
glGenTextures (1, &texture_id);
if (use_texture_rectangle)
target = GL_TEXTURE_RECTANGLE_ARB;
else
target = GL_TEXTURE_2D;
glBindTexture (target, texture_id);
glEnable (target);
glEnable (GL_SCISSOR_TEST);
glTexParameteri (target, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
glTexParameteri (target, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
glTexParameteri (target, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
glTexParameteri (target, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
n_rects = cairo_region_num_rectangles (region);
#define FLIP_Y(_y) (unscaled_window_height - (_y))
for (i = 0; i < n_rects; i++)
{
cairo_region_get_rectangle (region, i, &rect);
glScissor (rect.x * window_scale, FLIP_Y ((rect.y + rect.height) * window_scale),
rect.width * window_scale, rect.height * window_scale);
e = rect;
e.x *= sx;
e.y *= sy;
e.x += (int)device_x_offset;
e.y += (int)device_y_offset;
e.width *= sx;
e.height *= sy;
image = cairo_surface_map_to_image (surface, &e);
/* We might have a different alignment, stride or format, so allow overriding here if needed */
GDK_GL_CONTEXT_GET_CLASS (paint_context)->upload_texture (paint_context, image, e.width, e.height, target);
cairo_surface_unmap_image (surface, image);
if (use_texture_rectangle)
{
umax = rect.width * sx;
vmax = rect.height * sy;
}
else
{
umax = 1.0;
vmax = 1.0;
}
{
GdkTexturedQuad quad = {
rect.x * window_scale, FLIP_Y(rect.y * window_scale),
(rect.x + rect.width) * window_scale, FLIP_Y((rect.y + rect.height) * window_scale),
0, 0,
umax, vmax,
};
/* We don't want to combine the quads here, because they have different textures.
* And we don't want to upload the unused source areas to make it one texture. */
gdk_gl_texture_quads (paint_context, target, 1, &quad);
}
}
glDisable (GL_SCISSOR_TEST);
glDisable (target);
glDeleteTextures (1, &texture_id);
}