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/* cairo - a vector graphics library with display and print output
*
* Copyright © 2009 Eric Anholt
* Copyright © 2009 Chris Wilson
* Copyright © 2005,2010 Red Hat, Inc
* Copyright © 2011 Linaro Limited
* Copyright © 2011 Samsung Electronics
*
* This library is free software; you can redistribute it and/or
* modify it either under the terms of the GNU Lesser General Public
* License version 2.1 as published by the Free Software Foundation
* (the "LGPL") or, at your option, under the terms of the Mozilla
* Public License Version 1.1 (the "MPL"). If you do not alter this
* notice, a recipient may use your version of this file under either
* the MPL or the LGPL.
*
* You should have received a copy of the LGPL along with this library
* in the file COPYING-LGPL-2.1; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Suite 500, Boston, MA 02110-1335, USA
* You should have received a copy of the MPL along with this library
* in the file COPYING-MPL-1.1
*
* The contents of this file are subject to the Mozilla Public License
* Version 1.1 (the "License"); you may not use this file except in
* compliance with the License. You may obtain a copy of the License at
* http://www.mozilla.org/MPL/
*
* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY
* OF ANY KIND, either express or implied. See the LGPL or the MPL for
* the specific language governing rights and limitations.
*
* The Original Code is the cairo graphics library.
*
* The Initial Developer of the Original Code is Red Hat, Inc.
*
* Contributor(s):
* Benjamin Otte <otte@gnome.org>
* Carl Worth <cworth@cworth.org>
* Chris Wilson <chris@chris-wilson.co.uk>
* Eric Anholt <eric@anholt.net>
* Alexandros Frantzis <alexandros.frantzis@linaro.org>
* Henry Song <hsong@sisa.samsung.com>
* Martin Robinson <mrobinson@igalia.com>
*/
#include "cairoint.h"
#include "cairo-gl-private.h"
#include "cairo-composite-rectangles-private.h"
#include "cairo-clip-private.h"
#include "cairo-error-private.h"
#include "cairo-image-surface-private.h"
cairo_int_status_t
_cairo_gl_composite_set_source (cairo_gl_composite_t *setup,
const cairo_pattern_t *pattern,
const cairo_rectangle_int_t *sample,
const cairo_rectangle_int_t *extents,
cairo_bool_t use_texgen)
{
_cairo_gl_operand_destroy (&setup->src);
return _cairo_gl_operand_init (&setup->src, pattern, setup->dst,
sample, extents, use_texgen);
}
void
_cairo_gl_composite_set_source_operand (cairo_gl_composite_t *setup,
const cairo_gl_operand_t *source)
{
_cairo_gl_operand_destroy (&setup->src);
_cairo_gl_operand_copy (&setup->src, source);
}
void
_cairo_gl_composite_set_solid_source (cairo_gl_composite_t *setup,
const cairo_color_t *color)
{
_cairo_gl_operand_destroy (&setup->src);
_cairo_gl_solid_operand_init (&setup->src, color);
}
cairo_int_status_t
_cairo_gl_composite_set_mask (cairo_gl_composite_t *setup,
const cairo_pattern_t *pattern,
const cairo_rectangle_int_t *sample,
const cairo_rectangle_int_t *extents,
cairo_bool_t use_texgen)
{
_cairo_gl_operand_destroy (&setup->mask);
if (pattern == NULL)
return CAIRO_STATUS_SUCCESS;
return _cairo_gl_operand_init (&setup->mask, pattern, setup->dst,
sample, extents, use_texgen);
}
void
_cairo_gl_composite_set_mask_operand (cairo_gl_composite_t *setup,
const cairo_gl_operand_t *mask)
{
_cairo_gl_operand_destroy (&setup->mask);
if (mask)
_cairo_gl_operand_copy (&setup->mask, mask);
}
void
_cairo_gl_composite_set_spans (cairo_gl_composite_t *setup)
{
setup->spans = TRUE;
}
void
_cairo_gl_composite_set_multisample (cairo_gl_composite_t *setup)
{
setup->multisample = TRUE;
}
void
_cairo_gl_composite_set_clip_region (cairo_gl_composite_t *setup,
cairo_region_t *clip_region)
{
setup->clip_region = clip_region;
}
void
_cairo_gl_composite_set_clip (cairo_gl_composite_t *setup,
cairo_clip_t *clip)
{
setup->clip = clip;
}
static void
_cairo_gl_composite_bind_to_shader (cairo_gl_context_t *ctx,
cairo_gl_composite_t *setup)
{
_cairo_gl_shader_bind_matrix4f(ctx, ctx->current_shader->mvp_location,
ctx->modelviewprojection_matrix);
_cairo_gl_operand_bind_to_shader (ctx, &setup->src, CAIRO_GL_TEX_SOURCE);
_cairo_gl_operand_bind_to_shader (ctx, &setup->mask, CAIRO_GL_TEX_MASK);
}
static void
_cairo_gl_texture_set_filter (cairo_gl_context_t *ctx,
GLuint target,
cairo_filter_t filter)
{
switch (filter) {
case CAIRO_FILTER_FAST:
case CAIRO_FILTER_NEAREST:
glTexParameteri (target, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
glTexParameteri (target, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
break;
case CAIRO_FILTER_GOOD:
case CAIRO_FILTER_BEST:
case CAIRO_FILTER_BILINEAR:
glTexParameteri (target, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTexParameteri (target, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
break;
default:
case CAIRO_FILTER_GAUSSIAN:
ASSERT_NOT_REACHED;
}
}
static void
_cairo_gl_texture_set_extend (cairo_gl_context_t *ctx,
GLuint target,
cairo_extend_t extend)
{
GLint wrap_mode;
assert (! _cairo_gl_device_requires_power_of_two_textures (&ctx->base) ||
(extend != CAIRO_EXTEND_REPEAT && extend != CAIRO_EXTEND_REFLECT));
switch (extend) {
case CAIRO_EXTEND_NONE:
if (ctx->gl_flavor == CAIRO_GL_FLAVOR_ES)
wrap_mode = GL_CLAMP_TO_EDGE;
else
wrap_mode = GL_CLAMP_TO_BORDER;
break;
case CAIRO_EXTEND_PAD:
wrap_mode = GL_CLAMP_TO_EDGE;
break;
case CAIRO_EXTEND_REPEAT:
if (ctx->has_npot_repeat)
wrap_mode = GL_REPEAT;
else
wrap_mode = GL_CLAMP_TO_EDGE;
break;
case CAIRO_EXTEND_REFLECT:
if (ctx->has_npot_repeat)
wrap_mode = GL_MIRRORED_REPEAT;
else
wrap_mode = GL_CLAMP_TO_EDGE;
break;
default:
wrap_mode = 0;
}
if (likely (wrap_mode)) {
glTexParameteri (target, GL_TEXTURE_WRAP_S, wrap_mode);
glTexParameteri (target, GL_TEXTURE_WRAP_T, wrap_mode);
}
}
static void
_cairo_gl_context_setup_operand (cairo_gl_context_t *ctx,
cairo_gl_tex_t tex_unit,
cairo_gl_operand_t *operand,
unsigned int vertex_offset,
cairo_bool_t vertex_size_changed)
{
cairo_gl_dispatch_t *dispatch = &ctx->dispatch;
cairo_bool_t needs_setup;
/* XXX: we need to do setup when switching from shaders
* to no shaders (or back) */
needs_setup = vertex_size_changed;
needs_setup |= _cairo_gl_operand_needs_setup (&ctx->operands[tex_unit],
operand,
vertex_offset);
if (needs_setup) {
_cairo_gl_composite_flush (ctx);
_cairo_gl_context_destroy_operand (ctx, tex_unit);
}
memcpy (&ctx->operands[tex_unit], operand, sizeof (cairo_gl_operand_t));
ctx->operands[tex_unit].vertex_offset = vertex_offset;
if (! needs_setup)
return;
switch (operand->type) {
default:
case CAIRO_GL_OPERAND_COUNT:
ASSERT_NOT_REACHED;
case CAIRO_GL_OPERAND_NONE:
break;
/* fall through */
case CAIRO_GL_OPERAND_CONSTANT:
break;
case CAIRO_GL_OPERAND_TEXTURE:
glActiveTexture (GL_TEXTURE0 + tex_unit);
glBindTexture (ctx->tex_target, operand->texture.tex);
_cairo_gl_texture_set_extend (ctx, ctx->tex_target,
operand->texture.attributes.extend);
_cairo_gl_texture_set_filter (ctx, ctx->tex_target,
operand->texture.attributes.filter);
if (! operand->texture.texgen) {
dispatch->VertexAttribPointer (CAIRO_GL_TEXCOORD0_ATTRIB_INDEX + tex_unit, 2,
GL_FLOAT, GL_FALSE, ctx->vertex_size,
ctx->vb + vertex_offset);
dispatch->EnableVertexAttribArray (CAIRO_GL_TEXCOORD0_ATTRIB_INDEX + tex_unit);
}
break;
case CAIRO_GL_OPERAND_LINEAR_GRADIENT:
case CAIRO_GL_OPERAND_RADIAL_GRADIENT_A0:
case CAIRO_GL_OPERAND_RADIAL_GRADIENT_NONE:
case CAIRO_GL_OPERAND_RADIAL_GRADIENT_EXT:
glActiveTexture (GL_TEXTURE0 + tex_unit);
glBindTexture (ctx->tex_target, operand->gradient.gradient->tex);
_cairo_gl_texture_set_extend (ctx, ctx->tex_target, operand->gradient.extend);
_cairo_gl_texture_set_filter (ctx, ctx->tex_target, CAIRO_FILTER_BILINEAR);
if (! operand->gradient.texgen) {
dispatch->VertexAttribPointer (CAIRO_GL_TEXCOORD0_ATTRIB_INDEX + tex_unit, 2,
GL_FLOAT, GL_FALSE, ctx->vertex_size,
ctx->vb + vertex_offset);
dispatch->EnableVertexAttribArray (CAIRO_GL_TEXCOORD0_ATTRIB_INDEX + tex_unit);
}
break;
}
}
static void
_cairo_gl_context_setup_spans (cairo_gl_context_t *ctx,
cairo_bool_t spans_enabled,
unsigned int vertex_size,
unsigned int vertex_offset)
{
cairo_gl_dispatch_t *dispatch = &ctx->dispatch;
if (! spans_enabled) {
dispatch->DisableVertexAttribArray (CAIRO_GL_COLOR_ATTRIB_INDEX);
ctx->spans = FALSE;
return;
}
dispatch->VertexAttribPointer (CAIRO_GL_COLOR_ATTRIB_INDEX, 4,
GL_UNSIGNED_BYTE, GL_TRUE, vertex_size,
ctx->vb + vertex_offset);
dispatch->EnableVertexAttribArray (CAIRO_GL_COLOR_ATTRIB_INDEX);
ctx->spans = TRUE;
}
void
_cairo_gl_context_destroy_operand (cairo_gl_context_t *ctx,
cairo_gl_tex_t tex_unit)
{
cairo_gl_dispatch_t *dispatch = &ctx->dispatch;
if (!_cairo_gl_context_is_flushed (ctx))
_cairo_gl_composite_flush (ctx);
switch (ctx->operands[tex_unit].type) {
default:
case CAIRO_GL_OPERAND_COUNT:
ASSERT_NOT_REACHED;
case CAIRO_GL_OPERAND_NONE:
break;
/* fall through */
case CAIRO_GL_OPERAND_CONSTANT:
break;
case CAIRO_GL_OPERAND_TEXTURE:
dispatch->DisableVertexAttribArray (CAIRO_GL_TEXCOORD0_ATTRIB_INDEX + tex_unit);
break;
case CAIRO_GL_OPERAND_LINEAR_GRADIENT:
case CAIRO_GL_OPERAND_RADIAL_GRADIENT_A0:
case CAIRO_GL_OPERAND_RADIAL_GRADIENT_NONE:
case CAIRO_GL_OPERAND_RADIAL_GRADIENT_EXT:
dispatch->DisableVertexAttribArray (CAIRO_GL_TEXCOORD0_ATTRIB_INDEX + tex_unit);
break;
}
memset (&ctx->operands[tex_unit], 0, sizeof (cairo_gl_operand_t));
}
static void
_cairo_gl_set_operator (cairo_gl_context_t *ctx,
cairo_operator_t op,
cairo_bool_t component_alpha)
{
struct {
GLenum src;
GLenum dst;
} blend_factors[] = {
{ GL_ZERO, GL_ZERO }, /* Clear */
{ GL_ONE, GL_ZERO }, /* Source */
{ GL_ONE, GL_ONE_MINUS_SRC_ALPHA }, /* Over */
{ GL_DST_ALPHA, GL_ZERO }, /* In */
{ GL_ONE_MINUS_DST_ALPHA, GL_ZERO }, /* Out */
{ GL_DST_ALPHA, GL_ONE_MINUS_SRC_ALPHA }, /* Atop */
{ GL_ZERO, GL_ONE }, /* Dest */
{ GL_ONE_MINUS_DST_ALPHA, GL_ONE }, /* DestOver */
{ GL_ZERO, GL_SRC_ALPHA }, /* DestIn */
{ GL_ZERO, GL_ONE_MINUS_SRC_ALPHA }, /* DestOut */
{ GL_ONE_MINUS_DST_ALPHA, GL_SRC_ALPHA }, /* DestAtop */
{ GL_ONE_MINUS_DST_ALPHA, GL_ONE_MINUS_SRC_ALPHA }, /* Xor */
{ GL_ONE, GL_ONE }, /* Add */
};
GLenum src_factor, dst_factor;
assert (op < ARRAY_LENGTH (blend_factors));
/* different dst and component_alpha changes cause flushes elsewhere */
if (ctx->current_operator != op)
_cairo_gl_composite_flush (ctx);
ctx->current_operator = op;
src_factor = blend_factors[op].src;
dst_factor = blend_factors[op].dst;
/* Even when the user requests CAIRO_CONTENT_COLOR, we use GL_RGBA
* due to texture filtering of GL_CLAMP_TO_BORDER. So fix those
* bits in that case.
*/
if (ctx->current_target->base.content == CAIRO_CONTENT_COLOR) {
if (src_factor == GL_ONE_MINUS_DST_ALPHA)
src_factor = GL_ZERO;
if (src_factor == GL_DST_ALPHA)
src_factor = GL_ONE;
}
if (component_alpha) {
if (dst_factor == GL_ONE_MINUS_SRC_ALPHA)
dst_factor = GL_ONE_MINUS_SRC_COLOR;
if (dst_factor == GL_SRC_ALPHA)
dst_factor = GL_SRC_COLOR;
}
if (ctx->current_target->base.content == CAIRO_CONTENT_ALPHA) {
glBlendFuncSeparate (GL_ZERO, GL_ZERO, src_factor, dst_factor);
} else if (ctx->current_target->base.content == CAIRO_CONTENT_COLOR) {
glBlendFuncSeparate (src_factor, dst_factor, GL_ONE, GL_ONE);
} else {
glBlendFunc (src_factor, dst_factor);
}
}
static cairo_status_t
_cairo_gl_composite_begin_component_alpha (cairo_gl_context_t *ctx,
cairo_gl_composite_t *setup)
{
cairo_gl_shader_t *pre_shader = NULL;
cairo_status_t status;
/* For CLEAR, cairo's rendering equation (quoting Owen's description in:
* http://lists.cairographics.org/archives/cairo/2005-August/004992.html)
* is:
* mask IN clip ? src OP dest : dest
* or more simply:
* mask IN CLIP ? 0 : dest
*
* where the ternary operator A ? B : C is (A * B) + ((1 - A) * C).
*
* The model we use in _cairo_gl_set_operator() is Render's:
* src IN mask IN clip OP dest
* which would boil down to:
* 0 (bounded by the extents of the drawing).
*
* However, we can do a Render operation using an opaque source
* and DEST_OUT to produce:
* 1 IN mask IN clip DEST_OUT dest
* which is
* mask IN clip ? 0 : dest
*/
if (setup->op == CAIRO_OPERATOR_CLEAR) {
_cairo_gl_solid_operand_init (&setup->src, CAIRO_COLOR_WHITE);
setup->op = CAIRO_OPERATOR_DEST_OUT;
}
/*
* implements component-alpha %CAIRO_OPERATOR_OVER using two passes of
* the simpler operations %CAIRO_OPERATOR_DEST_OUT and %CAIRO_OPERATOR_ADD.
*
* From http://anholt.livejournal.com/32058.html:
*
* The trouble is that component-alpha rendering requires two different sources
* for blending: one for the source value to the blender, which is the
* per-channel multiplication of source and mask, and one for the source alpha
* for multiplying with the destination channels, which is the multiplication
* of the source channels by the mask alpha. So the equation for Over is:
*
* dst.A = src.A * mask.A + (1 - (src.A * mask.A)) * dst.A
* dst.R = src.R * mask.R + (1 - (src.A * mask.R)) * dst.R
* dst.G = src.G * mask.G + (1 - (src.A * mask.G)) * dst.G
* dst.B = src.B * mask.B + (1 - (src.A * mask.B)) * dst.B
*
* But we can do some simpler operations, right? How about PictOpOutReverse,
* which has a source factor of 0 and dest factor of (1 - source alpha). We
* can get the source alpha value (srca.X = src.A * mask.X) out of the texture
* blenders pretty easily. So we can do a component-alpha OutReverse, which
* gets us:
*
* dst.A = 0 + (1 - (src.A * mask.A)) * dst.A
* dst.R = 0 + (1 - (src.A * mask.R)) * dst.R
* dst.G = 0 + (1 - (src.A * mask.G)) * dst.G
* dst.B = 0 + (1 - (src.A * mask.B)) * dst.B
*
* OK. And if an op doesn't use the source alpha value for the destination
* factor, then we can do the channel multiplication in the texture blenders
* to get the source value, and ignore the source alpha that we wouldn't use.
* We've supported this in the Radeon driver for a long time. An example would
* be PictOpAdd, which does:
*
* dst.A = src.A * mask.A + dst.A
* dst.R = src.R * mask.R + dst.R
* dst.G = src.G * mask.G + dst.G
* dst.B = src.B * mask.B + dst.B
*
* Hey, this looks good! If we do a PictOpOutReverse and then a PictOpAdd right
* after it, we get:
*
* dst.A = src.A * mask.A + ((1 - (src.A * mask.A)) * dst.A)
* dst.R = src.R * mask.R + ((1 - (src.A * mask.R)) * dst.R)
* dst.G = src.G * mask.G + ((1 - (src.A * mask.G)) * dst.G)
* dst.B = src.B * mask.B + ((1 - (src.A * mask.B)) * dst.B)
*
* This two-pass trickery could be avoided using a new GL extension that
* lets two values come out of the shader and into the blend unit.
*/
if (setup->op == CAIRO_OPERATOR_OVER) {
setup->op = CAIRO_OPERATOR_ADD;
status = _cairo_gl_get_shader_by_type (ctx,
&setup->src,
&setup->mask,
setup->spans,
CAIRO_GL_SHADER_IN_CA_SOURCE_ALPHA,
&pre_shader);
if (unlikely (status))
return status;
}
if (ctx->pre_shader != pre_shader)
_cairo_gl_composite_flush (ctx);
ctx->pre_shader = pre_shader;
return CAIRO_STATUS_SUCCESS;
}
static void
_scissor_to_doubles (cairo_gl_surface_t *surface,
double x1, double y1,
double x2, double y2)
{
double height;
height = y2 - y1;
if (_cairo_gl_surface_is_texture (surface) == FALSE)
y1 = surface->height - (y1 + height);
glScissor (x1, y1, x2 - x1, height);
glEnable (GL_SCISSOR_TEST);
}
void
_cairo_gl_scissor_to_rectangle (cairo_gl_surface_t *surface,
const cairo_rectangle_int_t *r)
{
_scissor_to_doubles (surface, r->x, r->y, r->x+r->width, r->y+r->height);
}
static void
_scissor_to_box (cairo_gl_surface_t *surface,
const cairo_box_t *box)
{
double x1, y1, x2, y2;
_cairo_box_to_doubles (box, &x1, &y1, &x2, &y2);
_scissor_to_doubles (surface, x1, y1, x2, y2);
}
static cairo_bool_t
_cairo_gl_composite_setup_vbo (cairo_gl_context_t *ctx,
unsigned int size_per_vertex)
{
cairo_bool_t vertex_size_changed = ctx->vertex_size != size_per_vertex;
if (vertex_size_changed) {
ctx->vertex_size = size_per_vertex;
_cairo_gl_composite_flush (ctx);
}
if (_cairo_gl_context_is_flushed (ctx)) {
ctx->dispatch.VertexAttribPointer (CAIRO_GL_VERTEX_ATTRIB_INDEX, 2,
GL_FLOAT, GL_FALSE, size_per_vertex,
ctx->vb);
ctx->dispatch.EnableVertexAttribArray (CAIRO_GL_VERTEX_ATTRIB_INDEX);
}
return vertex_size_changed;
}
static void
_disable_stencil_buffer (void)
{
glDisable (GL_STENCIL_TEST);
glDepthMask (GL_FALSE);
}
static cairo_int_status_t
_cairo_gl_composite_setup_painted_clipping (cairo_gl_composite_t *setup,
cairo_gl_context_t *ctx,
int vertex_size)
{
cairo_int_status_t status = CAIRO_INT_STATUS_SUCCESS;
cairo_gl_surface_t *dst = setup->dst;
cairo_clip_t *clip = setup->clip;
if (clip->num_boxes == 1 && clip->path == NULL) {
_scissor_to_box (dst, &clip->boxes[0]);
goto disable_stencil_buffer_and_return;
}
if (! _cairo_gl_ensure_stencil (ctx, setup->dst)) {
status = CAIRO_INT_STATUS_UNSUPPORTED;
goto disable_stencil_buffer_and_return;
}
/* We only want to clear the part of the stencil buffer
* that we are about to use. It also does not hurt to
* scissor around the painted clip. */
_cairo_gl_scissor_to_rectangle (dst, _cairo_clip_get_extents (clip));
/* The clip is not rectangular, so use the stencil buffer. */
glDepthMask (GL_TRUE);
glEnable (GL_STENCIL_TEST);
/* Texture surfaces have private depth/stencil buffers, so we can
* rely on any previous clip being cached there. */
if (_cairo_gl_surface_is_texture (setup->dst)) {
cairo_clip_t *old_clip = setup->dst->clip_on_stencil_buffer;
if (_cairo_clip_equal (old_clip, setup->clip))
goto activate_stencil_buffer_and_return;
if (old_clip) {
_cairo_clip_destroy (setup->dst->clip_on_stencil_buffer);
}
setup->dst->clip_on_stencil_buffer = _cairo_clip_copy (setup->clip);
}
glClearStencil (0);
glClear (GL_STENCIL_BUFFER_BIT);
glStencilOp (GL_REPLACE, GL_REPLACE, GL_REPLACE);
glStencilFunc (GL_EQUAL, 1, 0xffffffff);
glColorMask (0, 0, 0, 0);
status = _cairo_gl_msaa_compositor_draw_clip (ctx, setup, clip);
if (unlikely (status)) {
glColorMask (1, 1, 1, 1);
goto disable_stencil_buffer_and_return;
}
/* We want to only render to the stencil buffer, so draw everything now.
Flushing also unbinds the VBO, which we want to rebind for regular
drawing. */
_cairo_gl_composite_flush (ctx);
_cairo_gl_composite_setup_vbo (ctx, vertex_size);
activate_stencil_buffer_and_return:
glColorMask (1, 1, 1, 1);
glStencilOp (GL_KEEP, GL_KEEP, GL_KEEP);
glStencilFunc (GL_EQUAL, 1, 0xffffffff);
return CAIRO_INT_STATUS_SUCCESS;
disable_stencil_buffer_and_return:
_disable_stencil_buffer ();
return status;
}
static cairo_int_status_t
_cairo_gl_composite_setup_clipping (cairo_gl_composite_t *setup,
cairo_gl_context_t *ctx,
int vertex_size)
{
cairo_bool_t clip_changing = TRUE;
cairo_bool_t clip_region_changing = TRUE;
if (! ctx->clip && ! setup->clip && ! setup->clip_region && ! ctx->clip_region)
goto disable_all_clipping;
clip_changing = ! _cairo_clip_equal (ctx->clip, setup->clip);
clip_region_changing = ! cairo_region_equal (ctx->clip_region, setup->clip_region);
if (! _cairo_gl_context_is_flushed (ctx) &&
(clip_region_changing || clip_changing))
_cairo_gl_composite_flush (ctx);
assert (!setup->clip_region || !setup->clip);
/* setup->clip is only used by the msaa compositor and setup->clip_region
* only by the other compositors, so it's safe to wait to clean up obsolete
* clips. */
if (clip_region_changing) {
cairo_region_destroy (ctx->clip_region);
ctx->clip_region = cairo_region_reference (setup->clip_region);
}
if (clip_changing) {
_cairo_clip_destroy (ctx->clip);
ctx->clip = _cairo_clip_copy (setup->clip);
}
/* For clip regions, we scissor right before drawing. */
if (setup->clip_region)
goto disable_all_clipping;
if (setup->clip)
return _cairo_gl_composite_setup_painted_clipping (setup, ctx,
vertex_size);
disable_all_clipping:
_disable_stencil_buffer ();
glDisable (GL_SCISSOR_TEST);
return CAIRO_INT_STATUS_SUCCESS;
}
cairo_status_t
_cairo_gl_set_operands_and_operator (cairo_gl_composite_t *setup,
cairo_gl_context_t *ctx)
{
unsigned int dst_size, src_size, mask_size, vertex_size;
cairo_status_t status;
cairo_gl_shader_t *shader;
cairo_bool_t component_alpha;
cairo_bool_t vertex_size_changed;
component_alpha =
setup->mask.type == CAIRO_GL_OPERAND_TEXTURE &&
setup->mask.texture.attributes.has_component_alpha;
/* Do various magic for component alpha */
if (component_alpha) {
status = _cairo_gl_composite_begin_component_alpha (ctx, setup);
if (unlikely (status))
return status;
} else {
if (ctx->pre_shader) {
_cairo_gl_composite_flush (ctx);
ctx->pre_shader = NULL;
}
}
status = _cairo_gl_get_shader_by_type (ctx,
&setup->src,
&setup->mask,
setup->spans,
component_alpha ?
CAIRO_GL_SHADER_IN_CA_SOURCE :
CAIRO_GL_SHADER_IN_NORMAL,
&shader);
if (unlikely (status)) {
ctx->pre_shader = NULL;
return status;
}
if (ctx->current_shader != shader)
_cairo_gl_composite_flush (ctx);
status = CAIRO_STATUS_SUCCESS;
dst_size = 2 * sizeof (GLfloat);
src_size = _cairo_gl_operand_get_vertex_size (&setup->src);
mask_size = _cairo_gl_operand_get_vertex_size (&setup->mask);
vertex_size = dst_size + src_size + mask_size;
if (setup->spans)
vertex_size += sizeof (GLfloat);
vertex_size_changed = _cairo_gl_composite_setup_vbo (ctx, vertex_size);
_cairo_gl_context_setup_operand (ctx, CAIRO_GL_TEX_SOURCE, &setup->src, dst_size, vertex_size_changed);
_cairo_gl_context_setup_operand (ctx, CAIRO_GL_TEX_MASK, &setup->mask, dst_size + src_size, vertex_size_changed);
_cairo_gl_context_setup_spans (ctx, setup->spans, vertex_size,
dst_size + src_size + mask_size);
_cairo_gl_set_operator (ctx, setup->op, component_alpha);
if (_cairo_gl_context_is_flushed (ctx)) {
if (ctx->pre_shader) {
_cairo_gl_set_shader (ctx, ctx->pre_shader);
_cairo_gl_composite_bind_to_shader (ctx, setup);
}
_cairo_gl_set_shader (ctx, shader);
_cairo_gl_composite_bind_to_shader (ctx, setup);
}
return status;
}
cairo_status_t
_cairo_gl_composite_begin (cairo_gl_composite_t *setup,
cairo_gl_context_t **ctx_out)
{
cairo_gl_context_t *ctx;
cairo_status_t status;
assert (setup->dst);
status = _cairo_gl_context_acquire (setup->dst->base.device, &ctx);
if (unlikely (status))
return status;
_cairo_gl_context_set_destination (ctx, setup->dst, setup->multisample);
glEnable (GL_BLEND);
status = _cairo_gl_set_operands_and_operator (setup, ctx);
if (unlikely (status))
goto FAIL;
status = _cairo_gl_composite_setup_clipping (setup, ctx, ctx->vertex_size);
if (unlikely (status))
goto FAIL;
*ctx_out = ctx;
FAIL:
if (unlikely (status))
status = _cairo_gl_context_release (ctx, status);
return status;
}
static inline void
_cairo_gl_composite_draw_tristrip (cairo_gl_context_t *ctx)
{
cairo_array_t* indices = &ctx->tristrip_indices;
const unsigned short *indices_array = _cairo_array_index_const (indices, 0);
if (ctx->pre_shader) {
cairo_gl_shader_t *prev_shader = ctx->current_shader;
_cairo_gl_set_shader (ctx, ctx->pre_shader);
_cairo_gl_set_operator (ctx, CAIRO_OPERATOR_DEST_OUT, TRUE);
glDrawElements (GL_TRIANGLE_STRIP, _cairo_array_num_elements (indices), GL_UNSIGNED_SHORT, indices_array);
_cairo_gl_set_shader (ctx, prev_shader);
_cairo_gl_set_operator (ctx, CAIRO_OPERATOR_ADD, TRUE);
}
glDrawElements (GL_TRIANGLE_STRIP, _cairo_array_num_elements (indices), GL_UNSIGNED_SHORT, indices_array);
_cairo_array_truncate (indices, 0);
}
static inline void
_cairo_gl_composite_draw_triangles (cairo_gl_context_t *ctx,
unsigned int count)
{
if (! ctx->pre_shader) {
glDrawArrays (GL_TRIANGLES, 0, count);
} else {
cairo_gl_shader_t *prev_shader = ctx->current_shader;
_cairo_gl_set_shader (ctx, ctx->pre_shader);
_cairo_gl_set_operator (ctx, CAIRO_OPERATOR_DEST_OUT, TRUE);
glDrawArrays (GL_TRIANGLES, 0, count);
_cairo_gl_set_shader (ctx, prev_shader);
_cairo_gl_set_operator (ctx, CAIRO_OPERATOR_ADD, TRUE);
glDrawArrays (GL_TRIANGLES, 0, count);
}
}
static void
_cairo_gl_composite_draw_triangles_with_clip_region (cairo_gl_context_t *ctx,
unsigned int count)
{
int i, num_rectangles;
if (!ctx->clip_region) {
_cairo_gl_composite_draw_triangles (ctx, count);
return;
}
num_rectangles = cairo_region_num_rectangles (ctx->clip_region);
for (i = 0; i < num_rectangles; i++) {
cairo_rectangle_int_t rect;
cairo_region_get_rectangle (ctx->clip_region, i, &rect);
_cairo_gl_scissor_to_rectangle (ctx->current_target, &rect);
_cairo_gl_composite_draw_triangles (ctx, count);
}
}
static void
_cairo_gl_composite_unmap_vertex_buffer (cairo_gl_context_t *ctx)
{
ctx->vb_offset = 0;
}
void
_cairo_gl_composite_flush (cairo_gl_context_t *ctx)
{
unsigned int count;
int i;
if (_cairo_gl_context_is_flushed (ctx))
return;
count = ctx->vb_offset / ctx->vertex_size;
_cairo_gl_composite_unmap_vertex_buffer (ctx);
if (ctx->primitive_type == CAIRO_GL_PRIMITIVE_TYPE_TRISTRIPS) {
_cairo_gl_composite_draw_tristrip (ctx);
} else {
assert (ctx->primitive_type == CAIRO_GL_PRIMITIVE_TYPE_TRIANGLES);
_cairo_gl_composite_draw_triangles_with_clip_region (ctx, count);
}
for (i = 0; i < ARRAY_LENGTH (ctx->glyph_cache); i++)
_cairo_gl_glyph_cache_unlock (&ctx->glyph_cache[i]);
}
static void
_cairo_gl_composite_prepare_buffer (cairo_gl_context_t *ctx,
unsigned int n_vertices,
cairo_gl_primitive_type_t primitive_type)
{
if (ctx->primitive_type != primitive_type) {
_cairo_gl_composite_flush (ctx);
ctx->primitive_type = primitive_type;
}
assert(ctx->vbo_size > 0);
if (ctx->vb_offset + n_vertices * ctx->vertex_size > ctx->vbo_size)
_cairo_gl_composite_flush (ctx);
}
static inline void
_cairo_gl_composite_emit_vertex (cairo_gl_context_t *ctx,
GLfloat x, GLfloat y)
{
GLfloat *vb = (GLfloat *) (void *) &ctx->vb[ctx->vb_offset];
*vb++ = x;
*vb++ = y;
_cairo_gl_operand_emit (&ctx->operands[CAIRO_GL_TEX_SOURCE], &vb, x, y);
_cairo_gl_operand_emit (&ctx->operands[CAIRO_GL_TEX_MASK ], &vb, x, y);
ctx->vb_offset += ctx->vertex_size;
}
static inline void
_cairo_gl_composite_emit_alpha_vertex (cairo_gl_context_t *ctx,
GLfloat x, GLfloat y, uint8_t alpha)
{
GLfloat *vb = (GLfloat *) (void *) &ctx->vb[ctx->vb_offset];
union fi {
float f;
GLbyte bytes[4];
} fi;
*vb++ = x;
*vb++ = y;
_cairo_gl_operand_emit (&ctx->operands[CAIRO_GL_TEX_SOURCE], &vb, x, y);
_cairo_gl_operand_emit (&ctx->operands[CAIRO_GL_TEX_MASK ], &vb, x, y);
fi.bytes[0] = 0;
fi.bytes[1] = 0;
fi.bytes[2] = 0;
fi.bytes[3] = alpha;
*vb++ = fi.f;
ctx->vb_offset += ctx->vertex_size;
}
static void
_cairo_gl_composite_emit_point (cairo_gl_context_t *ctx,
const cairo_point_t *point)
{
_cairo_gl_composite_emit_vertex (ctx,
_cairo_fixed_to_double (point->x),
_cairo_fixed_to_double (point->y));
}
static void
_cairo_gl_composite_emit_rect (cairo_gl_context_t *ctx,
GLfloat x1, GLfloat y1,
GLfloat x2, GLfloat y2)
{
_cairo_gl_composite_prepare_buffer (ctx, 6,
CAIRO_GL_PRIMITIVE_TYPE_TRIANGLES);
_cairo_gl_composite_emit_vertex (ctx, x1, y1);
_cairo_gl_composite_emit_vertex (ctx, x2, y1);
_cairo_gl_composite_emit_vertex (ctx, x1, y2);
_cairo_gl_composite_emit_vertex (ctx, x2, y1);
_cairo_gl_composite_emit_vertex (ctx, x2, y2);
_cairo_gl_composite_emit_vertex (ctx, x1, y2);
}
cairo_gl_emit_rect_t
_cairo_gl_context_choose_emit_rect (cairo_gl_context_t *ctx)
{
return _cairo_gl_composite_emit_rect;
}
void
_cairo_gl_context_emit_rect (cairo_gl_context_t *ctx,
GLfloat x1, GLfloat y1,
GLfloat x2, GLfloat y2)
{
_cairo_gl_composite_emit_rect (ctx, x1, y1, x2, y2);
}
static void
_cairo_gl_composite_emit_span (cairo_gl_context_t *ctx,
GLfloat x1, GLfloat y1,
GLfloat x2, GLfloat y2,
uint8_t alpha)
{
_cairo_gl_composite_prepare_buffer (ctx, 6,
CAIRO_GL_PRIMITIVE_TYPE_TRIANGLES);
_cairo_gl_composite_emit_alpha_vertex (ctx, x1, y1, alpha);
_cairo_gl_composite_emit_alpha_vertex (ctx, x2, y1, alpha);
_cairo_gl_composite_emit_alpha_vertex (ctx, x1, y2, alpha);
_cairo_gl_composite_emit_alpha_vertex (ctx, x2, y1, alpha);
_cairo_gl_composite_emit_alpha_vertex (ctx, x2, y2, alpha);
_cairo_gl_composite_emit_alpha_vertex (ctx, x1, y2, alpha);
}
static void
_cairo_gl_composite_emit_solid_span (cairo_gl_context_t *ctx,
GLfloat x1, GLfloat y1,
GLfloat x2, GLfloat y2,
uint8_t alpha)
{
GLfloat *v;
union fi {
float f;
GLbyte bytes[4];
} fi;
_cairo_gl_composite_prepare_buffer (ctx, 6,
CAIRO_GL_PRIMITIVE_TYPE_TRIANGLES);
v = (GLfloat *) (void *) &ctx->vb[ctx->vb_offset];
v[15] = v[ 6] = v[0] = x1;
v[10] = v[ 4] = v[1] = y1;
v[12] = v[ 9] = v[3] = x2;
v[16] = v[13] = v[7] = y2;
fi.bytes[0] = 0;
fi.bytes[1] = 0;
fi.bytes[2] = 0;
fi.bytes[3] = alpha;
v[17] =v[14] = v[11] = v[8] = v[5] = v[2] = fi.f;
ctx->vb_offset += 6*3 * sizeof(GLfloat);
}
cairo_gl_emit_span_t
_cairo_gl_context_choose_emit_span (cairo_gl_context_t *ctx)
{
if (ctx->operands[CAIRO_GL_TEX_MASK].type != CAIRO_GL_OPERAND_NONE) {
switch (ctx->operands[CAIRO_GL_TEX_MASK].type) {
default:
case CAIRO_GL_OPERAND_COUNT:
ASSERT_NOT_REACHED;
case CAIRO_GL_OPERAND_NONE:
case CAIRO_GL_OPERAND_CONSTANT:
break;
case CAIRO_GL_OPERAND_LINEAR_GRADIENT:
case CAIRO_GL_OPERAND_RADIAL_GRADIENT_A0:
case CAIRO_GL_OPERAND_RADIAL_GRADIENT_NONE:
case CAIRO_GL_OPERAND_RADIAL_GRADIENT_EXT:
if (!ctx->operands[CAIRO_GL_TEX_MASK].gradient.texgen)
return _cairo_gl_composite_emit_span;
break;
case CAIRO_GL_OPERAND_TEXTURE:
if (!ctx->operands[CAIRO_GL_TEX_MASK].texture.texgen)
return _cairo_gl_composite_emit_span;
break;
}
}
switch (ctx->operands[CAIRO_GL_TEX_SOURCE].type) {
default:
case CAIRO_GL_OPERAND_COUNT:
ASSERT_NOT_REACHED;
case CAIRO_GL_OPERAND_NONE:
case CAIRO_GL_OPERAND_CONSTANT:
break;
case CAIRO_GL_OPERAND_LINEAR_GRADIENT:
case CAIRO_GL_OPERAND_RADIAL_GRADIENT_A0:
case CAIRO_GL_OPERAND_RADIAL_GRADIENT_NONE:
case CAIRO_GL_OPERAND_RADIAL_GRADIENT_EXT:
if (!ctx->operands[CAIRO_GL_TEX_SOURCE].gradient.texgen)
return _cairo_gl_composite_emit_span;
break;
case CAIRO_GL_OPERAND_TEXTURE:
if (!ctx->operands[CAIRO_GL_TEX_SOURCE].texture.texgen)
return _cairo_gl_composite_emit_span;
}
return _cairo_gl_composite_emit_solid_span;
}
static inline void
_cairo_gl_composite_emit_glyph_vertex (cairo_gl_context_t *ctx,
GLfloat x, GLfloat y,
GLfloat glyph_x, GLfloat glyph_y)
{
GLfloat *vb = (GLfloat *) (void *) &ctx->vb[ctx->vb_offset];
*vb++ = x;
*vb++ = y;
_cairo_gl_operand_emit (&ctx->operands[CAIRO_GL_TEX_SOURCE], &vb, x, y);
*vb++ = glyph_x;
*vb++ = glyph_y;
ctx->vb_offset += ctx->vertex_size;
}
static void
_cairo_gl_composite_emit_glyph (cairo_gl_context_t *ctx,
GLfloat x1, GLfloat y1,
GLfloat x2, GLfloat y2,
GLfloat glyph_x1, GLfloat glyph_y1,
GLfloat glyph_x2, GLfloat glyph_y2)
{
_cairo_gl_composite_prepare_buffer (ctx, 6,
CAIRO_GL_PRIMITIVE_TYPE_TRIANGLES);
_cairo_gl_composite_emit_glyph_vertex (ctx, x1, y1, glyph_x1, glyph_y1);
_cairo_gl_composite_emit_glyph_vertex (ctx, x2, y1, glyph_x2, glyph_y1);
_cairo_gl_composite_emit_glyph_vertex (ctx, x1, y2, glyph_x1, glyph_y2);
_cairo_gl_composite_emit_glyph_vertex (ctx, x2, y1, glyph_x2, glyph_y1);
_cairo_gl_composite_emit_glyph_vertex (ctx, x2, y2, glyph_x2, glyph_y2);
_cairo_gl_composite_emit_glyph_vertex (ctx, x1, y2, glyph_x1, glyph_y2);
}
static void
_cairo_gl_composite_emit_solid_glyph (cairo_gl_context_t *ctx,
GLfloat x1, GLfloat y1,
GLfloat x2, GLfloat y2,
GLfloat glyph_x1, GLfloat glyph_y1,
GLfloat glyph_x2, GLfloat glyph_y2)
{
GLfloat *v;
_cairo_gl_composite_prepare_buffer (ctx, 6,
CAIRO_GL_PRIMITIVE_TYPE_TRIANGLES);
v = (GLfloat *) (void *) &ctx->vb[ctx->vb_offset];
v[20] = v[ 8] = v[0] = x1;
v[13] = v[ 5] = v[1] = y1;
v[22] = v[10] = v[2] = glyph_x1;
v[15] = v[ 7] = v[3] = glyph_y1;
v[16] = v[12] = v[4] = x2;
v[18] = v[14] = v[6] = glyph_x2;
v[21] = v[17] = v[ 9] = y2;
v[23] = v[19] = v[11] = glyph_y2;
ctx->vb_offset += 4 * 6 * sizeof (GLfloat);
}
cairo_gl_emit_glyph_t
_cairo_gl_context_choose_emit_glyph (cairo_gl_context_t *ctx)
{
switch (ctx->operands[CAIRO_GL_TEX_SOURCE].type) {
default:
case CAIRO_GL_OPERAND_COUNT:
ASSERT_NOT_REACHED;
case CAIRO_GL_OPERAND_NONE:
case CAIRO_GL_OPERAND_CONSTANT:
return _cairo_gl_composite_emit_solid_glyph;
case CAIRO_GL_OPERAND_LINEAR_GRADIENT:
case CAIRO_GL_OPERAND_RADIAL_GRADIENT_A0:
case CAIRO_GL_OPERAND_RADIAL_GRADIENT_NONE:
case CAIRO_GL_OPERAND_RADIAL_GRADIENT_EXT:
case CAIRO_GL_OPERAND_TEXTURE:
return _cairo_gl_composite_emit_glyph;
}
}
void
_cairo_gl_composite_fini (cairo_gl_composite_t *setup)
{
_cairo_gl_operand_destroy (&setup->src);
_cairo_gl_operand_destroy (&setup->mask);
}
cairo_status_t
_cairo_gl_composite_set_operator (cairo_gl_composite_t *setup,
cairo_operator_t op,
cairo_bool_t assume_component_alpha)
{
if (assume_component_alpha) {
if (op != CAIRO_OPERATOR_CLEAR &&
op != CAIRO_OPERATOR_OVER &&
op != CAIRO_OPERATOR_ADD)
return UNSUPPORTED ("unsupported component alpha operator");
} else {
if (! _cairo_gl_operator_is_supported (op))
return UNSUPPORTED ("unsupported operator");
}
setup->op = op;
return CAIRO_STATUS_SUCCESS;
}
cairo_status_t
_cairo_gl_composite_init (cairo_gl_composite_t *setup,
cairo_operator_t op,
cairo_gl_surface_t *dst,
cairo_bool_t assume_component_alpha)
{
cairo_status_t status;
memset (setup, 0, sizeof (cairo_gl_composite_t));
status = _cairo_gl_composite_set_operator (setup, op,
assume_component_alpha);
if (status)
return status;
setup->dst = dst;
setup->clip_region = dst->clip_region;
return CAIRO_STATUS_SUCCESS;
}
static cairo_int_status_t
_cairo_gl_composite_append_vertex_indices (cairo_gl_context_t *ctx,
int number_of_new_indices)
{
cairo_int_status_t status = CAIRO_INT_STATUS_SUCCESS;
cairo_array_t *indices = &ctx->tristrip_indices;
int number_of_indices = _cairo_array_num_elements (indices);
unsigned short current_vertex_index = 0;
int i;
assert (number_of_new_indices > 0);
/* If any preexisting triangle triangle strip indices exist on this
context, we insert a set of degenerate triangles from the last
preexisting vertex to our first one. */
if (number_of_indices > 0) {
const unsigned short *indices_array = _cairo_array_index_const (indices, 0);
current_vertex_index = indices_array[number_of_indices - 1];
status = _cairo_array_append (indices, &current_vertex_index);
if (unlikely (status))
return status;
current_vertex_index++;
status =_cairo_array_append (indices, &current_vertex_index);
if (unlikely (status))
return status;
}
for (i = 0; i < number_of_new_indices; i++) {
status = _cairo_array_append (indices, &current_vertex_index);
current_vertex_index++;
if (unlikely (status))
return status;
}
return CAIRO_STATUS_SUCCESS;
}
cairo_int_status_t
_cairo_gl_composite_emit_quad_as_tristrip (cairo_gl_context_t *ctx,
cairo_gl_composite_t *setup,
const cairo_point_t quad[4])
{
_cairo_gl_composite_prepare_buffer (ctx, 4,
CAIRO_GL_PRIMITIVE_TYPE_TRISTRIPS);
_cairo_gl_composite_emit_point (ctx, &quad[0]);
_cairo_gl_composite_emit_point (ctx, &quad[1]);
/* Cairo stores quad vertices in counter-clockwise order, but we need to
emit them from top to bottom in the triangle strip, so we need to reverse
the order of the last two vertices. */
_cairo_gl_composite_emit_point (ctx, &quad[3]);
_cairo_gl_composite_emit_point (ctx, &quad[2]);
return _cairo_gl_composite_append_vertex_indices (ctx, 4);
}
cairo_int_status_t
_cairo_gl_composite_emit_triangle_as_tristrip (cairo_gl_context_t *ctx,
cairo_gl_composite_t *setup,
const cairo_point_t triangle[3])
{
_cairo_gl_composite_prepare_buffer (ctx, 3,
CAIRO_GL_PRIMITIVE_TYPE_TRISTRIPS);
_cairo_gl_composite_emit_point (ctx, &triangle[0]);
_cairo_gl_composite_emit_point (ctx, &triangle[1]);
_cairo_gl_composite_emit_point (ctx, &triangle[2]);
return _cairo_gl_composite_append_vertex_indices (ctx, 3);
}