/* 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 * Carl Worth * Chris Wilson * Eric Anholt * Alexandros Frantzis * Henry Song * Martin Robinson */ #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_gl_operand_destroy (&setup->src); return _cairo_gl_operand_init (&setup->src, pattern, setup->dst, sample, extents); } 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_gl_operand_destroy (&setup->mask); if (pattern == NULL) return CAIRO_STATUS_SUCCESS; return _cairo_gl_operand_init (&setup->mask, pattern, setup->dst, sample, extents); } 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_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, "ModelViewProjectionMatrix", 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_size, unsigned int vertex_offset) { 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 = ctx->vertex_size != vertex_size; 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); dispatch->VertexAttribPointer (CAIRO_GL_TEXCOORD0_ATTRIB_INDEX + tex_unit, 2, GL_FLOAT, GL_FALSE, 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); dispatch->VertexAttribPointer (CAIRO_GL_TEXCOORD0_ATTRIB_INDEX + tex_unit, 2, GL_FLOAT, GL_FALSE, 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, unsigned int vertex_size, unsigned int vertex_offset) { cairo_gl_dispatch_t *dispatch = &ctx->dispatch; 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); } static void _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 void _cairo_gl_composite_setup_vbo (cairo_gl_context_t *ctx, unsigned int size_per_vertex) { if (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); } ctx->vertex_size = size_per_vertex; } 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 we cannot reduce the clip to a rectangular region, we clip using the stencil buffer. */ glDisable (GL_SCISSOR_TEST); if (! _cairo_gl_ensure_stencil (ctx, setup->dst)) { status = CAIRO_INT_STATUS_UNSUPPORTED; goto disable_stencil_buffer_and_return; } glDepthMask (GL_TRUE); glEnable (GL_STENCIL_TEST); 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); 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) { if (! _cairo_gl_context_is_flushed (ctx) && (! cairo_region_equal (ctx->clip_region, setup->clip_region) || ! _cairo_clip_equal (ctx->clip, setup->clip))) _cairo_gl_composite_flush (ctx); cairo_region_destroy (ctx->clip_region); ctx->clip_region = cairo_region_reference (setup->clip_region); _cairo_clip_destroy (ctx->clip); ctx->clip = _cairo_clip_copy (setup->clip); assert (!setup->clip_region || !setup->clip); if (ctx->clip_region) { _disable_stencil_buffer (); glEnable (GL_SCISSOR_TEST); return CAIRO_INT_STATUS_SUCCESS; } if (ctx->clip) return _cairo_gl_composite_setup_painted_clipping (setup, ctx, vertex_size); _disable_stencil_buffer (); glDisable (GL_SCISSOR_TEST); return CAIRO_INT_STATUS_SUCCESS; } cairo_status_t _cairo_gl_composite_begin_multisample (cairo_gl_composite_t *setup, cairo_gl_context_t **ctx_out, cairo_bool_t multisampling) { unsigned int dst_size, src_size, mask_size, vertex_size; cairo_gl_context_t *ctx; cairo_status_t status; cairo_bool_t component_alpha; cairo_gl_shader_t *shader; 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, multisampling); glEnable (GL_BLEND); 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)) goto FAIL; } 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; goto FAIL; } 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.type); mask_size = _cairo_gl_operand_get_vertex_size (setup->mask.type); vertex_size = dst_size + src_size + mask_size; if (setup->spans) vertex_size += sizeof (GLfloat); _cairo_gl_composite_setup_vbo (ctx, vertex_size); _cairo_gl_context_setup_operand (ctx, CAIRO_GL_TEX_SOURCE, &setup->src, vertex_size, dst_size); _cairo_gl_context_setup_operand (ctx, CAIRO_GL_TEX_MASK, &setup->mask, vertex_size, dst_size + src_size); if (setup->spans) _cairo_gl_context_setup_spans (ctx, vertex_size, dst_size + src_size + mask_size); else ctx->dispatch.DisableVertexAttribArray (CAIRO_GL_COLOR_ATTRIB_INDEX); _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); } status = _cairo_gl_composite_setup_clipping (setup, ctx, vertex_size); if (unlikely (status)) goto FAIL; *ctx_out = ctx; FAIL: if (unlikely (status)) status = _cairo_gl_context_release (ctx, status); return status; } cairo_status_t _cairo_gl_composite_begin (cairo_gl_composite_t *setup, cairo_gl_context_t **ctx_out) { return _cairo_gl_composite_begin_multisample (setup, ctx_out, FALSE); } 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); _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; } if (ctx->vb_offset + n_vertices * ctx->vertex_size > CAIRO_GL_VBO_SIZE) _cairo_gl_composite_flush (ctx); } static inline void _cairo_gl_composite_emit_vertex (cairo_gl_context_t *ctx, GLfloat x, GLfloat y, uint8_t alpha) { 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); if (ctx->spans) { union fi { float f; GLbyte bytes[4]; } fi; 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, uint8_t alpha) { _cairo_gl_composite_emit_vertex (ctx, _cairo_fixed_to_double (point->x), _cairo_fixed_to_double (point->y), alpha); } void _cairo_gl_composite_emit_rect (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_vertex (ctx, x1, y1, alpha); _cairo_gl_composite_emit_vertex (ctx, x2, y1, alpha); _cairo_gl_composite_emit_vertex (ctx, x1, y2, alpha); _cairo_gl_composite_emit_vertex (ctx, x2, y1, alpha); _cairo_gl_composite_emit_vertex (ctx, x2, y2, alpha); _cairo_gl_composite_emit_vertex (ctx, x1, y2, alpha); } 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; } 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); } 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_init (cairo_gl_composite_t *setup, cairo_operator_t op, cairo_gl_surface_t *dst, cairo_bool_t assume_component_alpha) { memset (setup, 0, sizeof (cairo_gl_composite_t)); 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->dst = dst; setup->op = op; 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, ¤t_vertex_index); if (unlikely (status)) return status; current_vertex_index++; status =_cairo_array_append (indices, ¤t_vertex_index); if (unlikely (status)) return status; } for (i = 0; i < number_of_new_indices; i++) { status = _cairo_array_append (indices, ¤t_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], 0); _cairo_gl_composite_emit_point (ctx, &quad[1], 0); /* 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], 0); _cairo_gl_composite_emit_point (ctx, &quad[2], 0); 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], 0); _cairo_gl_composite_emit_point (ctx, &triangle[1], 0); _cairo_gl_composite_emit_point (ctx, &triangle[2], 0); return _cairo_gl_composite_append_vertex_indices (ctx, 3); }