/* cairo - a vector graphics library with display and print output * * Copyright © 2009 Eric Anholt * Copyright © 2009 Chris Wilson * Copyright © 2005,2010 Red Hat, Inc * * 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 */ #include "cairoint.h" #include "cairo-error-private.h" #include "cairo-gl-private.h" static cairo_int_status_t _cairo_gl_create_gradient_texture (cairo_gl_surface_t *dst, const cairo_gradient_pattern_t *pattern, cairo_gl_gradient_t **gradient) { cairo_gl_context_t *ctx; cairo_status_t status; status = _cairo_gl_context_acquire (dst->base.device, &ctx); if (unlikely (status)) return status; status = _cairo_gl_gradient_create (ctx, pattern->n_stops, pattern->stops, gradient); return _cairo_gl_context_release (ctx, status); } /** * Like cairo_pattern_acquire_surface(), but returns a matrix that transforms * from dest to src coords. */ static cairo_status_t _cairo_gl_pattern_texture_setup (cairo_gl_operand_t *operand, const cairo_pattern_t *src, cairo_gl_surface_t *dst, int src_x, int src_y, int dst_x, int dst_y, int width, int height) { cairo_status_t status; cairo_matrix_t m; cairo_gl_surface_t *surface; cairo_surface_attributes_t *attributes; attributes = &operand->texture.attributes; status = _cairo_pattern_acquire_surface (src, &dst->base, src_x, src_y, width, height, CAIRO_PATTERN_ACQUIRE_NONE, (cairo_surface_t **) &surface, attributes); if (unlikely (status)) return status; if (_cairo_gl_device_requires_power_of_two_textures (dst->base.device) && (attributes->extend == CAIRO_EXTEND_REPEAT || attributes->extend == CAIRO_EXTEND_REFLECT)) { _cairo_pattern_release_surface (src, &surface->base, attributes); return UNSUPPORTED ("EXT_texture_rectangle with repeat/reflect"); } assert (surface->base.backend == &_cairo_gl_surface_backend); assert (_cairo_gl_surface_is_texture (surface)); operand->type = CAIRO_GL_OPERAND_TEXTURE; operand->texture.surface = surface; operand->texture.tex = surface->tex; /* Translate the matrix from * (unnormalized src -> unnormalized src) to * (unnormalized dst -> unnormalized src) */ cairo_matrix_init_translate (&m, src_x - dst_x + attributes->x_offset, src_y - dst_y + attributes->y_offset); cairo_matrix_multiply (&attributes->matrix, &m, &attributes->matrix); /* Translate the matrix from * (unnormalized dst -> unnormalized src) to * (unnormalized dst -> normalized src) */ if (_cairo_gl_device_requires_power_of_two_textures (dst->base.device)) { cairo_matrix_init_scale (&m, 1.0, 1.0); } else { cairo_matrix_init_scale (&m, 1.0 / surface->width, 1.0 / surface->height); } cairo_matrix_multiply (&attributes->matrix, &attributes->matrix, &m); return CAIRO_STATUS_SUCCESS; } static cairo_status_t _cairo_gl_solid_operand_init (cairo_gl_operand_t *operand, const cairo_color_t *color) { operand->type = CAIRO_GL_OPERAND_CONSTANT; operand->constant.color[0] = color->red * color->alpha; operand->constant.color[1] = color->green * color->alpha; operand->constant.color[2] = color->blue * color->alpha; operand->constant.color[3] = color->alpha; return CAIRO_STATUS_SUCCESS; } static cairo_status_t _cairo_gl_gradient_operand_init (cairo_gl_operand_t *operand, cairo_gl_surface_t *dst, const cairo_pattern_t *pattern) { const cairo_gradient_pattern_t *gradient = (const cairo_gradient_pattern_t *)pattern; cairo_status_t status; if (! _cairo_gl_device_has_glsl (dst->base.device)) return CAIRO_INT_STATUS_UNSUPPORTED; if (gradient->base.type == CAIRO_PATTERN_TYPE_LINEAR) { cairo_linear_pattern_t *linear = (cairo_linear_pattern_t *) gradient; double x0, y0, x1, y1; x0 = _cairo_fixed_to_double (linear->p1.x); x1 = _cairo_fixed_to_double (linear->p2.x); y0 = _cairo_fixed_to_double (linear->p1.y); y1 = _cairo_fixed_to_double (linear->p2.y); status = _cairo_gl_create_gradient_texture (dst, gradient, &operand->linear.gradient); if (unlikely (status)) return status; /* Translation matrix from the destination fragment coordinates * (pixels from lower left = 0,0) to the coordinates in the */ cairo_matrix_init_translate (&operand->linear.m, -x0, -y0); cairo_matrix_multiply (&operand->linear.m, &pattern->matrix, &operand->linear.m); cairo_matrix_translate (&operand->linear.m, 0, dst->height); cairo_matrix_scale (&operand->linear.m, 1.0, -1.0); operand->linear.segment_x = x1 - x0; operand->linear.segment_y = y1 - y0; operand->linear.extend = pattern->extend; operand->type = CAIRO_GL_OPERAND_LINEAR_GRADIENT; return CAIRO_STATUS_SUCCESS; } else { cairo_radial_pattern_t *radial = (cairo_radial_pattern_t *) gradient; double x0, y0, r0, x1, y1, r1; x0 = _cairo_fixed_to_double (radial->c1.x); x1 = _cairo_fixed_to_double (radial->c2.x); y0 = _cairo_fixed_to_double (radial->c1.y); y1 = _cairo_fixed_to_double (radial->c2.y); r0 = _cairo_fixed_to_double (radial->r1); r1 = _cairo_fixed_to_double (radial->r2); status = _cairo_gl_create_gradient_texture (dst, gradient, &operand->radial.gradient); if (unlikely (status)) return status; /* Translation matrix from the destination fragment coordinates * (pixels from lower left = 0,0) to the coordinates in the */ cairo_matrix_init_translate (&operand->radial.m, -x0, -y0); cairo_matrix_multiply (&operand->radial.m, &pattern->matrix, &operand->radial.m); cairo_matrix_translate (&operand->radial.m, 0, dst->height); cairo_matrix_scale (&operand->radial.m, 1.0, -1.0); operand->radial.circle_1_x = x1 - x0; operand->radial.circle_1_y = y1 - y0; operand->radial.radius_0 = r0; operand->radial.radius_1 = r1; operand->radial.extend = pattern->extend; operand->type = CAIRO_GL_OPERAND_RADIAL_GRADIENT; return CAIRO_STATUS_SUCCESS; } return CAIRO_INT_STATUS_UNSUPPORTED; } static void _cairo_gl_operand_destroy (cairo_gl_operand_t *operand) { switch (operand->type) { case CAIRO_GL_OPERAND_CONSTANT: break; case CAIRO_GL_OPERAND_LINEAR_GRADIENT: _cairo_gl_gradient_destroy (operand->linear.gradient); break; case CAIRO_GL_OPERAND_RADIAL_GRADIENT: _cairo_gl_gradient_destroy (operand->radial.gradient); break; case CAIRO_GL_OPERAND_TEXTURE: _cairo_pattern_release_surface (NULL, /* XXX */ &operand->texture.surface->base, &operand->texture.attributes); break; default: case CAIRO_GL_OPERAND_COUNT: ASSERT_NOT_REACHED; case CAIRO_GL_OPERAND_NONE: case CAIRO_GL_OPERAND_SPANS: break; } operand->type = CAIRO_GL_OPERAND_NONE; } static cairo_int_status_t _cairo_gl_operand_init (cairo_gl_operand_t *operand, const cairo_pattern_t *pattern, cairo_gl_surface_t *dst, int src_x, int src_y, int dst_x, int dst_y, int width, int height) { cairo_status_t status; switch (pattern->type) { case CAIRO_PATTERN_TYPE_SOLID: return _cairo_gl_solid_operand_init (operand, &((cairo_solid_pattern_t *) pattern)->color); case CAIRO_PATTERN_TYPE_LINEAR: case CAIRO_PATTERN_TYPE_RADIAL: status = _cairo_gl_gradient_operand_init (operand, dst, pattern); if (status != CAIRO_INT_STATUS_UNSUPPORTED) return status; /* fall through */ default: case CAIRO_PATTERN_TYPE_SURFACE: return _cairo_gl_pattern_texture_setup (operand, pattern, dst, src_x, src_y, dst_x, dst_y, width, height); } } cairo_int_status_t _cairo_gl_composite_set_source (cairo_gl_composite_t *setup, const cairo_pattern_t *pattern, int src_x, int src_y, int dst_x, int dst_y, int width, int height) { _cairo_gl_operand_destroy (&setup->src); return _cairo_gl_operand_init (&setup->src, pattern, setup->dst, src_x, src_y, dst_x, dst_y, width, height); } cairo_int_status_t _cairo_gl_composite_set_mask (cairo_gl_composite_t *setup, const cairo_pattern_t *pattern, int src_x, int src_y, int dst_x, int dst_y, int width, int height) { _cairo_gl_operand_destroy (&setup->mask); if (pattern == NULL) return CAIRO_STATUS_SUCCESS; return _cairo_gl_operand_init (&setup->mask, pattern, setup->dst, src_x, src_y, dst_x, dst_y, width, height); } void _cairo_gl_composite_set_mask_spans (cairo_gl_composite_t *setup) { _cairo_gl_operand_destroy (&setup->mask); setup->mask.type = CAIRO_GL_OPERAND_SPANS; } void _cairo_gl_composite_set_clip_region (cairo_gl_composite_t *setup, cairo_region_t *clip_region) { setup->clip_region = clip_region; } static void _cairo_gl_operand_bind_to_shader (cairo_gl_context_t *ctx, cairo_gl_operand_t *operand, cairo_gl_tex_t tex_unit) { char uniform_name[50]; char *custom_part; static const char *names[] = { "source", "mask" }; strcpy (uniform_name, names[tex_unit]); custom_part = uniform_name + strlen (names[tex_unit]); switch (operand->type) { default: case CAIRO_GL_OPERAND_COUNT: ASSERT_NOT_REACHED; case CAIRO_GL_OPERAND_NONE: case CAIRO_GL_OPERAND_SPANS: break; case CAIRO_GL_OPERAND_CONSTANT: strcpy (custom_part, "_constant"); _cairo_gl_shader_bind_vec4 (ctx, uniform_name, operand->constant.color[0], operand->constant.color[1], operand->constant.color[2], operand->constant.color[3]); break; case CAIRO_GL_OPERAND_LINEAR_GRADIENT: strcpy (custom_part, "_matrix"); _cairo_gl_shader_bind_matrix (ctx, uniform_name, &operand->linear.m); strcpy (custom_part, "_segment"); _cairo_gl_shader_bind_vec2 (ctx, uniform_name, operand->linear.segment_x, operand->linear.segment_y); strcpy (custom_part, "_sampler"); _cairo_gl_shader_bind_texture(ctx, uniform_name, tex_unit); break; case CAIRO_GL_OPERAND_RADIAL_GRADIENT: strcpy (custom_part, "_matrix"); _cairo_gl_shader_bind_matrix (ctx, uniform_name, &operand->radial.m); strcpy (custom_part, "_circle_1"); _cairo_gl_shader_bind_vec2 (ctx, uniform_name, operand->radial.circle_1_x, operand->radial.circle_1_y); strcpy (custom_part, "_radius_0"); _cairo_gl_shader_bind_float (ctx, uniform_name, operand->radial.radius_0); strcpy (custom_part, "_radius_1"); _cairo_gl_shader_bind_float (ctx, uniform_name, operand->radial.radius_1); strcpy (custom_part, "_sampler"); _cairo_gl_shader_bind_texture(ctx, uniform_name, tex_unit); break; case CAIRO_GL_OPERAND_TEXTURE: strcpy (custom_part, "_sampler"); _cairo_gl_shader_bind_texture(ctx, uniform_name, tex_unit); break; } } static void _cairo_gl_composite_bind_to_shader (cairo_gl_context_t *ctx, cairo_gl_composite_t *setup) { if (ctx->current_shader == NULL) return; _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_extend (cairo_gl_context_t *ctx, GLuint target, cairo_extend_t extend) { 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: glTexParameteri (target, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_BORDER); glTexParameteri (target, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_BORDER); break; case CAIRO_EXTEND_PAD: glTexParameteri (target, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE); glTexParameteri (target, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE); break; case CAIRO_EXTEND_REPEAT: glTexParameteri (target, GL_TEXTURE_WRAP_S, GL_REPEAT); glTexParameteri (target, GL_TEXTURE_WRAP_T, GL_REPEAT); break; case CAIRO_EXTEND_REFLECT: glTexParameteri (target, GL_TEXTURE_WRAP_S, GL_MIRRORED_REPEAT); glTexParameteri (target, GL_TEXTURE_WRAP_T, GL_MIRRORED_REPEAT); break; } } 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_operand_setup_fixed (cairo_gl_operand_t *operand, cairo_gl_tex_t tex_unit) { switch (operand->type) { case CAIRO_GL_OPERAND_CONSTANT: glTexEnvfv (GL_TEXTURE_ENV, GL_TEXTURE_ENV_COLOR, operand->constant.color); glTexEnvi (GL_TEXTURE_ENV, GL_SRC0_RGB, GL_CONSTANT); glTexEnvi (GL_TEXTURE_ENV, GL_SRC0_ALPHA, GL_CONSTANT); break; case CAIRO_GL_OPERAND_TEXTURE: glTexEnvi (GL_TEXTURE_ENV, GL_SRC0_RGB, GL_TEXTURE0 + tex_unit); glTexEnvi (GL_TEXTURE_ENV, GL_SRC0_ALPHA, GL_TEXTURE0 + tex_unit); break; case CAIRO_GL_OPERAND_SPANS: glTexEnvi (GL_TEXTURE_ENV, GL_SRC0_RGB, GL_PRIMARY_COLOR); glTexEnvi (GL_TEXTURE_ENV, GL_SRC0_ALPHA, GL_PRIMARY_COLOR); break; case CAIRO_GL_OPERAND_COUNT: default: ASSERT_NOT_REACHED; case CAIRO_GL_OPERAND_LINEAR_GRADIENT: case CAIRO_GL_OPERAND_RADIAL_GRADIENT: case CAIRO_GL_OPERAND_NONE: return; } switch (tex_unit) { case CAIRO_GL_TEX_TEMP: default: ASSERT_NOT_REACHED; break; case CAIRO_GL_TEX_SOURCE: glTexEnvi (GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_COMBINE); glTexEnvi (GL_TEXTURE_ENV, GL_COMBINE_RGB, GL_REPLACE); glTexEnvi (GL_TEXTURE_ENV, GL_COMBINE_ALPHA, GL_REPLACE); glTexEnvi (GL_TEXTURE_ENV, GL_OPERAND0_RGB, GL_SRC_COLOR); glTexEnvi (GL_TEXTURE_ENV, GL_OPERAND0_ALPHA, GL_SRC_ALPHA); break; case CAIRO_GL_TEX_MASK: glTexEnvi (GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_COMBINE); glTexEnvi (GL_TEXTURE_ENV, GL_COMBINE_RGB, GL_MODULATE); glTexEnvi (GL_TEXTURE_ENV, GL_COMBINE_ALPHA, GL_MODULATE); glTexEnvi (GL_TEXTURE_ENV, GL_SRC1_RGB, GL_PREVIOUS); glTexEnvi (GL_TEXTURE_ENV, GL_SRC1_ALPHA, GL_PREVIOUS); glTexEnvi (GL_TEXTURE_ENV, GL_OPERAND1_RGB, GL_SRC_COLOR); glTexEnvi (GL_TEXTURE_ENV, GL_OPERAND1_ALPHA, GL_SRC_ALPHA); if (operand->type == CAIRO_GL_OPERAND_TEXTURE && operand->texture.attributes.has_component_alpha) glTexEnvi (GL_TEXTURE_ENV, GL_OPERAND0_RGB, GL_SRC_COLOR); else glTexEnvi (GL_TEXTURE_ENV, GL_OPERAND0_RGB, GL_SRC_ALPHA); glTexEnvi (GL_TEXTURE_ENV, GL_OPERAND0_ALPHA, GL_SRC_ALPHA); break; } } static cairo_bool_t _cairo_gl_operand_needs_setup (cairo_gl_operand_t *dest, cairo_gl_operand_t *source, unsigned int vertex_offset) { if (dest->type != source->type) return TRUE; if (dest->vertex_offset != vertex_offset) return TRUE; switch (source->type) { case CAIRO_GL_OPERAND_NONE: case CAIRO_GL_OPERAND_SPANS: return FALSE; case CAIRO_GL_OPERAND_CONSTANT: return dest->constant.color[0] != source->constant.color[0] || dest->constant.color[1] != source->constant.color[1] || dest->constant.color[2] != source->constant.color[2] || dest->constant.color[3] != source->constant.color[3]; case CAIRO_GL_OPERAND_TEXTURE: return dest->texture.surface != source->texture.surface || dest->texture.attributes.extend != source->texture.attributes.extend || dest->texture.attributes.filter != source->texture.attributes.filter || dest->texture.attributes.has_component_alpha != source->texture.attributes.has_component_alpha; case CAIRO_GL_OPERAND_LINEAR_GRADIENT: case CAIRO_GL_OPERAND_RADIAL_GRADIENT: /* XXX: improve this */ return TRUE; default: case CAIRO_GL_OPERAND_COUNT: ASSERT_NOT_REACHED; break; } return TRUE; } 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_bool_t use_shaders) { 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; case CAIRO_GL_OPERAND_SPANS: glColorPointer (4, GL_UNSIGNED_BYTE, vertex_size, (void *) (uintptr_t) vertex_offset); glEnableClientState (GL_COLOR_ARRAY); /* fall through */ case CAIRO_GL_OPERAND_CONSTANT: if (! use_shaders) { glActiveTexture (GL_TEXTURE0 + tex_unit); /* Have to have a dummy texture bound in order to use the combiner unit. */ glBindTexture (ctx->tex_target, ctx->dummy_tex); glEnable (ctx->tex_target); } break; case CAIRO_GL_OPERAND_TEXTURE: glActiveTexture (GL_TEXTURE0 + tex_unit); glBindTexture (ctx->tex_target, operand->texture.tex); glEnable (ctx->tex_target); _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); glClientActiveTexture (GL_TEXTURE0 + tex_unit); glTexCoordPointer (2, GL_FLOAT, vertex_size, (void *) (uintptr_t) vertex_offset); glEnableClientState (GL_TEXTURE_COORD_ARRAY); break; case CAIRO_GL_OPERAND_LINEAR_GRADIENT: _cairo_gl_gradient_reference (operand->linear.gradient); glActiveTexture (GL_TEXTURE0 + tex_unit); glBindTexture (GL_TEXTURE_1D, operand->linear.gradient->tex); _cairo_gl_texture_set_extend (ctx, GL_TEXTURE_1D, operand->linear.extend); _cairo_gl_texture_set_filter (ctx, GL_TEXTURE_1D, CAIRO_FILTER_BILINEAR); glEnable (GL_TEXTURE_1D); break; case CAIRO_GL_OPERAND_RADIAL_GRADIENT: _cairo_gl_gradient_reference (operand->radial.gradient); glActiveTexture (GL_TEXTURE0 + tex_unit); glBindTexture (GL_TEXTURE_1D, operand->radial.gradient->tex); _cairo_gl_texture_set_extend (ctx, GL_TEXTURE_1D, operand->radial.extend); _cairo_gl_texture_set_filter (ctx, GL_TEXTURE_1D, CAIRO_FILTER_BILINEAR); glEnable (GL_TEXTURE_1D); break; } if (! use_shaders) _cairo_gl_operand_setup_fixed (operand, tex_unit); } void _cairo_gl_context_destroy_operand (cairo_gl_context_t *ctx, cairo_gl_tex_t tex_unit) { assert (_cairo_gl_context_is_flushed (ctx)); switch (ctx->operands[tex_unit].type) { default: case CAIRO_GL_OPERAND_COUNT: ASSERT_NOT_REACHED; case CAIRO_GL_OPERAND_NONE: break; case CAIRO_GL_OPERAND_SPANS: glDisableClientState (GL_COLOR_ARRAY); /* fall through */ case CAIRO_GL_OPERAND_CONSTANT: if (ctx->current_shader == NULL) { glActiveTexture (GL_TEXTURE0 + tex_unit); glDisable (ctx->tex_target); } break; case CAIRO_GL_OPERAND_TEXTURE: glActiveTexture (GL_TEXTURE0 + tex_unit); glDisable (ctx->tex_target); glClientActiveTexture (GL_TEXTURE0 + tex_unit); glDisableClientState (GL_TEXTURE_COORD_ARRAY); break; case CAIRO_GL_OPERAND_LINEAR_GRADIENT: _cairo_gl_gradient_destroy (ctx->operands[tex_unit].linear.gradient); glActiveTexture (GL_TEXTURE0 + tex_unit); glDisable (GL_TEXTURE_1D); break; case CAIRO_GL_OPERAND_RADIAL_GRADIENT: _cairo_gl_gradient_destroy (ctx->operands[tex_unit].radial.gradient); glActiveTexture (GL_TEXTURE0 + tex_unit); glDisable (GL_TEXTURE_1D); break; } memset (&ctx->operands[tex_unit], 0, sizeof (cairo_gl_operand_t)); } /* Swizzles the source for creating the "source alpha" value * (src.aaaa * mask.argb) required by component alpha rendering. */ static void _cairo_gl_set_src_alpha (cairo_gl_context_t *ctx, cairo_bool_t activate) { if (ctx->current_shader) return; glActiveTexture (GL_TEXTURE0); glTexEnvi (GL_TEXTURE_ENV, GL_OPERAND0_RGB, activate ? GL_SRC_ALPHA : GL_SRC_COLOR); } 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 unsigned int _cairo_gl_operand_get_vertex_size (cairo_gl_operand_type_t type) { switch (type) { default: case CAIRO_GL_OPERAND_COUNT: ASSERT_NOT_REACHED; case CAIRO_GL_OPERAND_NONE: case CAIRO_GL_OPERAND_CONSTANT: case CAIRO_GL_OPERAND_LINEAR_GRADIENT: case CAIRO_GL_OPERAND_RADIAL_GRADIENT: return 0; case CAIRO_GL_OPERAND_SPANS: return 4 * sizeof (GLbyte); case CAIRO_GL_OPERAND_TEXTURE: return 2 * sizeof (GLfloat); } } 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.type, setup->mask.type, 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; } cairo_status_t _cairo_gl_composite_begin (cairo_gl_composite_t *setup, cairo_gl_context_t **ctx_out) { 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; 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.type, setup->mask.type, 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 (ctx->vertex_size != vertex_size) { _cairo_gl_composite_flush (ctx); } _cairo_gl_context_set_destination (ctx, setup->dst); if (_cairo_gl_context_is_flushed (ctx)) { glBindBufferARB (GL_ARRAY_BUFFER_ARB, ctx->vbo); glVertexPointer (2, GL_FLOAT, vertex_size, NULL); glEnableClientState (GL_VERTEX_ARRAY); } _cairo_gl_context_setup_operand (ctx, CAIRO_GL_TEX_SOURCE, &setup->src, vertex_size, dst_size, shader != NULL); _cairo_gl_context_setup_operand (ctx, CAIRO_GL_TEX_MASK, &setup->mask, vertex_size, dst_size + src_size, shader != NULL); _cairo_gl_set_operator (ctx, setup->op, component_alpha); ctx->vertex_size = vertex_size; 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); } if (! _cairo_gl_context_is_flushed (ctx) && ! cairo_region_equal (ctx->clip_region, setup->clip_region)) _cairo_gl_composite_flush (ctx); cairo_region_destroy (ctx->clip_region); ctx->clip_region = cairo_region_reference (setup->clip_region); if (ctx->clip_region) glEnable (GL_SCISSOR_TEST); else glDisable (GL_SCISSOR_TEST); *ctx_out = ctx; FAIL: if (unlikely (status)) status = _cairo_gl_context_release (ctx, status); return status; } static inline void _cairo_gl_composite_draw (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); _cairo_gl_set_src_alpha (ctx, TRUE); glDrawArrays (GL_TRIANGLES, 0, count); _cairo_gl_set_src_alpha (ctx, FALSE); _cairo_gl_set_shader (ctx, prev_shader); _cairo_gl_set_operator (ctx, CAIRO_OPERATOR_ADD, TRUE); glDrawArrays (GL_TRIANGLES, 0, count); } } void _cairo_gl_composite_flush (cairo_gl_context_t *ctx) { unsigned int count; if (_cairo_gl_context_is_flushed (ctx)) return; count = ctx->vb_offset / ctx->vertex_size; glUnmapBufferARB (GL_ARRAY_BUFFER_ARB); ctx->vb = NULL; ctx->vb_offset = 0; if (ctx->clip_region) { int i, 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); glScissor (rect.x, rect.y, rect.width, rect.height); _cairo_gl_composite_draw (ctx, count); } } else { _cairo_gl_composite_draw (ctx, count); } } static void _cairo_gl_composite_prepare_buffer (cairo_gl_context_t *ctx, unsigned int n_vertices) { if (ctx->vb_offset + n_vertices * ctx->vertex_size > CAIRO_GL_VBO_SIZE) _cairo_gl_composite_flush (ctx); if (ctx->vb == NULL) { glBufferDataARB (GL_ARRAY_BUFFER_ARB, CAIRO_GL_VBO_SIZE, NULL, GL_STREAM_DRAW_ARB); ctx->vb = glMapBufferARB (GL_ARRAY_BUFFER_ARB, GL_WRITE_ONLY_ARB); } } static inline void _cairo_gl_operand_emit (cairo_gl_operand_t *operand, GLfloat ** vb, GLfloat x, GLfloat y, uint8_t alpha) { switch (operand->type) { default: case CAIRO_GL_OPERAND_COUNT: ASSERT_NOT_REACHED; case CAIRO_GL_OPERAND_NONE: case CAIRO_GL_OPERAND_CONSTANT: case CAIRO_GL_OPERAND_LINEAR_GRADIENT: case CAIRO_GL_OPERAND_RADIAL_GRADIENT: break; case CAIRO_GL_OPERAND_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; } break; case CAIRO_GL_OPERAND_TEXTURE: { cairo_surface_attributes_t *src_attributes = &operand->texture.attributes; double s = x; double t = y; cairo_matrix_transform_point (&src_attributes->matrix, &s, &t); *(*vb)++ = s; *(*vb)++ = t; } break; } } 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, alpha); _cairo_gl_operand_emit (&ctx->operands[CAIRO_GL_TEX_MASK ], &vb, x, y, alpha); ctx->vb_offset += ctx->vertex_size; } 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_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, 0); *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_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, const cairo_rectangle_int_t *rect) { 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; return CAIRO_STATUS_SUCCESS; }