/** * \file blend.c * Blending operations. */ /* * Mesa 3-D graphics library * * Copyright (C) 1999-2006 Brian Paul All Rights Reserved. * * Permission is hereby granted, free of charge, to any person obtaining a * copy of this software and associated documentation files (the "Software"), * to deal in the Software without restriction, including without limitation * the rights to use, copy, modify, merge, publish, distribute, sublicense, * and/or sell copies of the Software, and to permit persons to whom the * Software is furnished to do so, subject to the following conditions: * * The above copyright notice and this permission notice shall be included * in all copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR * OTHER DEALINGS IN THE SOFTWARE. */ #include "glheader.h" #include "blend.h" #include "context.h" #include "enums.h" #include "macros.h" #include "mtypes.h" /** * Check if given blend source factor is legal. * \return GL_TRUE if legal, GL_FALSE otherwise. */ static GLboolean legal_src_factor(const struct gl_context *ctx, GLenum factor) { switch (factor) { case GL_SRC_COLOR: case GL_ONE_MINUS_SRC_COLOR: case GL_ZERO: case GL_ONE: case GL_DST_COLOR: case GL_ONE_MINUS_DST_COLOR: case GL_SRC_ALPHA: case GL_ONE_MINUS_SRC_ALPHA: case GL_DST_ALPHA: case GL_ONE_MINUS_DST_ALPHA: case GL_SRC_ALPHA_SATURATE: return GL_TRUE; case GL_CONSTANT_COLOR: case GL_ONE_MINUS_CONSTANT_COLOR: case GL_CONSTANT_ALPHA: case GL_ONE_MINUS_CONSTANT_ALPHA: return _mesa_is_desktop_gl(ctx) || ctx->API == API_OPENGLES2; case GL_SRC1_COLOR: case GL_SRC1_ALPHA: case GL_ONE_MINUS_SRC1_COLOR: case GL_ONE_MINUS_SRC1_ALPHA: return _mesa_is_desktop_gl(ctx) && ctx->Extensions.ARB_blend_func_extended; default: return GL_FALSE; } } /** * Check if given blend destination factor is legal. * \return GL_TRUE if legal, GL_FALSE otherwise. */ static GLboolean legal_dst_factor(const struct gl_context *ctx, GLenum factor) { switch (factor) { case GL_DST_COLOR: case GL_ONE_MINUS_DST_COLOR: case GL_ZERO: case GL_ONE: case GL_SRC_COLOR: case GL_ONE_MINUS_SRC_COLOR: case GL_SRC_ALPHA: case GL_ONE_MINUS_SRC_ALPHA: case GL_DST_ALPHA: case GL_ONE_MINUS_DST_ALPHA: return GL_TRUE; case GL_CONSTANT_COLOR: case GL_ONE_MINUS_CONSTANT_COLOR: case GL_CONSTANT_ALPHA: case GL_ONE_MINUS_CONSTANT_ALPHA: return _mesa_is_desktop_gl(ctx) || ctx->API == API_OPENGLES2; case GL_SRC_ALPHA_SATURATE: return (_mesa_is_desktop_gl(ctx) && ctx->Extensions.ARB_blend_func_extended) || _mesa_is_gles3(ctx); case GL_SRC1_COLOR: case GL_SRC1_ALPHA: case GL_ONE_MINUS_SRC1_COLOR: case GL_ONE_MINUS_SRC1_ALPHA: return _mesa_is_desktop_gl(ctx) && ctx->Extensions.ARB_blend_func_extended; default: return GL_FALSE; } } /** * Check if src/dest RGB/A blend factors are legal. If not generate * a GL error. * \return GL_TRUE if factors are legal, GL_FALSE otherwise. */ static GLboolean validate_blend_factors(struct gl_context *ctx, const char *func, GLenum sfactorRGB, GLenum dfactorRGB, GLenum sfactorA, GLenum dfactorA) { if (!legal_src_factor(ctx, sfactorRGB)) { _mesa_error(ctx, GL_INVALID_ENUM, "%s(sfactorRGB = %s)", func, _mesa_lookup_enum_by_nr(sfactorRGB)); return GL_FALSE; } if (!legal_dst_factor(ctx, dfactorRGB)) { _mesa_error(ctx, GL_INVALID_ENUM, "%s(dfactorRGB = %s)", func, _mesa_lookup_enum_by_nr(dfactorRGB)); return GL_FALSE; } if (sfactorA != sfactorRGB && !legal_src_factor(ctx, sfactorA)) { _mesa_error(ctx, GL_INVALID_ENUM, "%s(sfactorA = %s)", func, _mesa_lookup_enum_by_nr(sfactorA)); return GL_FALSE; } if (dfactorA != dfactorRGB && !legal_dst_factor(ctx, dfactorA)) { _mesa_error(ctx, GL_INVALID_ENUM, "%s(dfactorA = %s)", func, _mesa_lookup_enum_by_nr(dfactorA)); return GL_FALSE; } return GL_TRUE; } /** * Specify the blending operation. * * \param sfactor source factor operator. * \param dfactor destination factor operator. * * \sa glBlendFunc, glBlendFuncSeparateEXT */ void GLAPIENTRY _mesa_BlendFunc( GLenum sfactor, GLenum dfactor ) { _mesa_BlendFuncSeparate(sfactor, dfactor, sfactor, dfactor); } static GLboolean blend_factor_is_dual_src(GLenum factor) { return (factor == GL_SRC1_COLOR || factor == GL_SRC1_ALPHA || factor == GL_ONE_MINUS_SRC1_COLOR || factor == GL_ONE_MINUS_SRC1_ALPHA); } static void update_uses_dual_src(struct gl_context *ctx, int buf) { ctx->Color.Blend[buf]._UsesDualSrc = (blend_factor_is_dual_src(ctx->Color.Blend[buf].SrcRGB) || blend_factor_is_dual_src(ctx->Color.Blend[buf].DstRGB) || blend_factor_is_dual_src(ctx->Color.Blend[buf].SrcA) || blend_factor_is_dual_src(ctx->Color.Blend[buf].DstA)); } /** * Set the separate blend source/dest factors for all draw buffers. * * \param sfactorRGB RGB source factor operator. * \param dfactorRGB RGB destination factor operator. * \param sfactorA alpha source factor operator. * \param dfactorA alpha destination factor operator. */ void GLAPIENTRY _mesa_BlendFuncSeparate( GLenum sfactorRGB, GLenum dfactorRGB, GLenum sfactorA, GLenum dfactorA ) { GLuint buf, numBuffers; GLboolean changed; GET_CURRENT_CONTEXT(ctx); if (MESA_VERBOSE & VERBOSE_API) _mesa_debug(ctx, "glBlendFuncSeparate %s %s %s %s\n", _mesa_lookup_enum_by_nr(sfactorRGB), _mesa_lookup_enum_by_nr(dfactorRGB), _mesa_lookup_enum_by_nr(sfactorA), _mesa_lookup_enum_by_nr(dfactorA)); if (!validate_blend_factors(ctx, "glBlendFuncSeparate", sfactorRGB, dfactorRGB, sfactorA, dfactorA)) { return; } numBuffers = ctx->Extensions.ARB_draw_buffers_blend ? ctx->Const.MaxDrawBuffers : 1; changed = GL_FALSE; for (buf = 0; buf < numBuffers; buf++) { if (ctx->Color.Blend[buf].SrcRGB != sfactorRGB || ctx->Color.Blend[buf].DstRGB != dfactorRGB || ctx->Color.Blend[buf].SrcA != sfactorA || ctx->Color.Blend[buf].DstA != dfactorA) { changed = GL_TRUE; break; } } if (!changed) return; FLUSH_VERTICES(ctx, _NEW_COLOR); for (buf = 0; buf < numBuffers; buf++) { ctx->Color.Blend[buf].SrcRGB = sfactorRGB; ctx->Color.Blend[buf].DstRGB = dfactorRGB; ctx->Color.Blend[buf].SrcA = sfactorA; ctx->Color.Blend[buf].DstA = dfactorA; update_uses_dual_src(ctx, buf); } ctx->Color._BlendFuncPerBuffer = GL_FALSE; if (ctx->Driver.BlendFuncSeparate) { ctx->Driver.BlendFuncSeparate(ctx, sfactorRGB, dfactorRGB, sfactorA, dfactorA); } } /** * Set blend source/dest factors for one color buffer/target. */ void GLAPIENTRY _mesa_BlendFunciARB(GLuint buf, GLenum sfactor, GLenum dfactor) { _mesa_BlendFuncSeparateiARB(buf, sfactor, dfactor, sfactor, dfactor); } /** * Set separate blend source/dest factors for one color buffer/target. */ void GLAPIENTRY _mesa_BlendFuncSeparateiARB(GLuint buf, GLenum sfactorRGB, GLenum dfactorRGB, GLenum sfactorA, GLenum dfactorA) { GET_CURRENT_CONTEXT(ctx); if (!ctx->Extensions.ARB_draw_buffers_blend) { _mesa_error(ctx, GL_INVALID_OPERATION, "glBlendFunc[Separate]i()"); return; } if (buf >= ctx->Const.MaxDrawBuffers) { _mesa_error(ctx, GL_INVALID_VALUE, "glBlendFuncSeparatei(buffer=%u)", buf); return; } if (!validate_blend_factors(ctx, "glBlendFuncSeparatei", sfactorRGB, dfactorRGB, sfactorA, dfactorA)) { return; } if (ctx->Color.Blend[buf].SrcRGB == sfactorRGB && ctx->Color.Blend[buf].DstRGB == dfactorRGB && ctx->Color.Blend[buf].SrcA == sfactorA && ctx->Color.Blend[buf].DstA == dfactorA) return; /* no change */ FLUSH_VERTICES(ctx, _NEW_COLOR); ctx->Color.Blend[buf].SrcRGB = sfactorRGB; ctx->Color.Blend[buf].DstRGB = dfactorRGB; ctx->Color.Blend[buf].SrcA = sfactorA; ctx->Color.Blend[buf].DstA = dfactorA; update_uses_dual_src(ctx, buf); ctx->Color._BlendFuncPerBuffer = GL_TRUE; if (ctx->Driver.BlendFuncSeparatei) { ctx->Driver.BlendFuncSeparatei(ctx, buf, sfactorRGB, dfactorRGB, sfactorA, dfactorA); } } /** * Check if given blend equation is legal. * \return GL_TRUE if legal, GL_FALSE otherwise. */ static GLboolean legal_blend_equation(const struct gl_context *ctx, GLenum mode) { switch (mode) { case GL_FUNC_ADD: case GL_FUNC_SUBTRACT: case GL_FUNC_REVERSE_SUBTRACT: return GL_TRUE; case GL_MIN: case GL_MAX: return ctx->Extensions.EXT_blend_minmax; default: return GL_FALSE; } } /* This is really an extension function! */ void GLAPIENTRY _mesa_BlendEquation( GLenum mode ) { GLuint buf, numBuffers; GLboolean changed; GET_CURRENT_CONTEXT(ctx); if (MESA_VERBOSE & VERBOSE_API) _mesa_debug(ctx, "glBlendEquation(%s)\n", _mesa_lookup_enum_by_nr(mode)); if (!legal_blend_equation(ctx, mode)) { _mesa_error(ctx, GL_INVALID_ENUM, "glBlendEquation"); return; } numBuffers = ctx->Extensions.ARB_draw_buffers_blend ? ctx->Const.MaxDrawBuffers : 1; changed = GL_FALSE; for (buf = 0; buf < numBuffers; buf++) { if (ctx->Color.Blend[buf].EquationRGB != mode || ctx->Color.Blend[buf].EquationA != mode) { changed = GL_TRUE; break; } } if (!changed) return; FLUSH_VERTICES(ctx, _NEW_COLOR); for (buf = 0; buf < numBuffers; buf++) { ctx->Color.Blend[buf].EquationRGB = mode; ctx->Color.Blend[buf].EquationA = mode; } ctx->Color._BlendEquationPerBuffer = GL_FALSE; if (ctx->Driver.BlendEquationSeparate) (*ctx->Driver.BlendEquationSeparate)( ctx, mode, mode ); } /** * Set blend equation for one color buffer/target. */ void GLAPIENTRY _mesa_BlendEquationiARB(GLuint buf, GLenum mode) { GET_CURRENT_CONTEXT(ctx); if (MESA_VERBOSE & VERBOSE_API) _mesa_debug(ctx, "glBlendEquationi(%u, %s)\n", buf, _mesa_lookup_enum_by_nr(mode)); if (buf >= ctx->Const.MaxDrawBuffers) { _mesa_error(ctx, GL_INVALID_VALUE, "glBlendFuncSeparatei(buffer=%u)", buf); return; } if (!legal_blend_equation(ctx, mode)) { _mesa_error(ctx, GL_INVALID_ENUM, "glBlendEquationi"); return; } if (ctx->Color.Blend[buf].EquationRGB == mode && ctx->Color.Blend[buf].EquationA == mode) return; /* no change */ FLUSH_VERTICES(ctx, _NEW_COLOR); ctx->Color.Blend[buf].EquationRGB = mode; ctx->Color.Blend[buf].EquationA = mode; ctx->Color._BlendEquationPerBuffer = GL_TRUE; if (ctx->Driver.BlendEquationSeparatei) ctx->Driver.BlendEquationSeparatei(ctx, buf, mode, mode); } void GLAPIENTRY _mesa_BlendEquationSeparate( GLenum modeRGB, GLenum modeA ) { GLuint buf, numBuffers; GLboolean changed; GET_CURRENT_CONTEXT(ctx); if (MESA_VERBOSE & VERBOSE_API) _mesa_debug(ctx, "glBlendEquationSeparateEXT(%s %s)\n", _mesa_lookup_enum_by_nr(modeRGB), _mesa_lookup_enum_by_nr(modeA)); if ( (modeRGB != modeA) && !ctx->Extensions.EXT_blend_equation_separate ) { _mesa_error(ctx, GL_INVALID_OPERATION, "glBlendEquationSeparateEXT not supported by driver"); return; } if (!legal_blend_equation(ctx, modeRGB)) { _mesa_error(ctx, GL_INVALID_ENUM, "glBlendEquationSeparateEXT(modeRGB)"); return; } if (!legal_blend_equation(ctx, modeA)) { _mesa_error(ctx, GL_INVALID_ENUM, "glBlendEquationSeparateEXT(modeA)"); return; } numBuffers = ctx->Extensions.ARB_draw_buffers_blend ? ctx->Const.MaxDrawBuffers : 1; changed = GL_FALSE; for (buf = 0; buf < numBuffers; buf++) { if (ctx->Color.Blend[buf].EquationRGB != modeRGB || ctx->Color.Blend[buf].EquationA != modeA) { changed = GL_TRUE; break; } } if (!changed) return; FLUSH_VERTICES(ctx, _NEW_COLOR); for (buf = 0; buf < numBuffers; buf++) { ctx->Color.Blend[buf].EquationRGB = modeRGB; ctx->Color.Blend[buf].EquationA = modeA; } ctx->Color._BlendEquationPerBuffer = GL_FALSE; if (ctx->Driver.BlendEquationSeparate) ctx->Driver.BlendEquationSeparate(ctx, modeRGB, modeA); } /** * Set separate blend equations for one color buffer/target. */ void GLAPIENTRY _mesa_BlendEquationSeparateiARB(GLuint buf, GLenum modeRGB, GLenum modeA) { GET_CURRENT_CONTEXT(ctx); if (MESA_VERBOSE & VERBOSE_API) _mesa_debug(ctx, "glBlendEquationSeparatei(%u, %s %s)\n", buf, _mesa_lookup_enum_by_nr(modeRGB), _mesa_lookup_enum_by_nr(modeA)); if (buf >= ctx->Const.MaxDrawBuffers) { _mesa_error(ctx, GL_INVALID_VALUE, "glBlendEquationSeparatei(buffer=%u)", buf); return; } if (!legal_blend_equation(ctx, modeRGB)) { _mesa_error(ctx, GL_INVALID_ENUM, "glBlendEquationSeparatei(modeRGB)"); return; } if (!legal_blend_equation(ctx, modeA)) { _mesa_error(ctx, GL_INVALID_ENUM, "glBlendEquationSeparatei(modeA)"); return; } if (ctx->Color.Blend[buf].EquationRGB == modeRGB && ctx->Color.Blend[buf].EquationA == modeA) return; /* no change */ FLUSH_VERTICES(ctx, _NEW_COLOR); ctx->Color.Blend[buf].EquationRGB = modeRGB; ctx->Color.Blend[buf].EquationA = modeA; ctx->Color._BlendEquationPerBuffer = GL_TRUE; if (ctx->Driver.BlendEquationSeparatei) ctx->Driver.BlendEquationSeparatei(ctx, buf, modeRGB, modeA); } /** * Set the blending color. * * \param red red color component. * \param green green color component. * \param blue blue color component. * \param alpha alpha color component. * * \sa glBlendColor(). * * Clamps the parameters and updates gl_colorbuffer_attrib::BlendColor. On a * change, flushes the vertices and notifies the driver via * dd_function_table::BlendColor callback. */ void GLAPIENTRY _mesa_BlendColor( GLclampf red, GLclampf green, GLclampf blue, GLclampf alpha ) { GLfloat tmp[4]; GET_CURRENT_CONTEXT(ctx); tmp[0] = red; tmp[1] = green; tmp[2] = blue; tmp[3] = alpha; if (TEST_EQ_4V(tmp, ctx->Color.BlendColorUnclamped)) return; FLUSH_VERTICES(ctx, _NEW_COLOR); COPY_4FV( ctx->Color.BlendColorUnclamped, tmp ); ctx->Color.BlendColor[0] = CLAMP(tmp[0], 0.0F, 1.0F); ctx->Color.BlendColor[1] = CLAMP(tmp[1], 0.0F, 1.0F); ctx->Color.BlendColor[2] = CLAMP(tmp[2], 0.0F, 1.0F); ctx->Color.BlendColor[3] = CLAMP(tmp[3], 0.0F, 1.0F); if (ctx->Driver.BlendColor) (*ctx->Driver.BlendColor)(ctx, ctx->Color.BlendColor); } /** * Specify the alpha test function. * * \param func alpha comparison function. * \param ref reference value. * * Verifies the parameters and updates gl_colorbuffer_attrib. * On a change, flushes the vertices and notifies the driver via * dd_function_table::AlphaFunc callback. */ void GLAPIENTRY _mesa_AlphaFunc( GLenum func, GLclampf ref ) { GET_CURRENT_CONTEXT(ctx); if (MESA_VERBOSE & VERBOSE_API) _mesa_debug(ctx, "glAlphaFunc(%s, %f)\n", _mesa_lookup_enum_by_nr(func), ref); switch (func) { case GL_NEVER: case GL_LESS: case GL_EQUAL: case GL_LEQUAL: case GL_GREATER: case GL_NOTEQUAL: case GL_GEQUAL: case GL_ALWAYS: if (ctx->Color.AlphaFunc == func && ctx->Color.AlphaRefUnclamped == ref) return; /* no change */ FLUSH_VERTICES(ctx, _NEW_COLOR); ctx->Color.AlphaFunc = func; ctx->Color.AlphaRefUnclamped = ref; ctx->Color.AlphaRef = CLAMP(ref, 0.0F, 1.0F); if (ctx->Driver.AlphaFunc) ctx->Driver.AlphaFunc(ctx, func, ctx->Color.AlphaRef); return; default: _mesa_error( ctx, GL_INVALID_ENUM, "glAlphaFunc(func)" ); return; } } /** * Specify a logic pixel operation for color index rendering. * * \param opcode operation. * * Verifies that \p opcode is a valid enum and updates gl_colorbuffer_attrib::LogicOp. * On a change, flushes the vertices and notifies the driver via the * dd_function_table::LogicOpcode callback. */ void GLAPIENTRY _mesa_LogicOp( GLenum opcode ) { GET_CURRENT_CONTEXT(ctx); if (MESA_VERBOSE & VERBOSE_API) _mesa_debug(ctx, "glLogicOp(%s)\n", _mesa_lookup_enum_by_nr(opcode)); switch (opcode) { case GL_CLEAR: case GL_SET: case GL_COPY: case GL_COPY_INVERTED: case GL_NOOP: case GL_INVERT: case GL_AND: case GL_NAND: case GL_OR: case GL_NOR: case GL_XOR: case GL_EQUIV: case GL_AND_REVERSE: case GL_AND_INVERTED: case GL_OR_REVERSE: case GL_OR_INVERTED: break; default: _mesa_error( ctx, GL_INVALID_ENUM, "glLogicOp" ); return; } if (ctx->Color.LogicOp == opcode) return; FLUSH_VERTICES(ctx, _NEW_COLOR); ctx->Color.LogicOp = opcode; if (ctx->Driver.LogicOpcode) ctx->Driver.LogicOpcode( ctx, opcode ); } void GLAPIENTRY _mesa_IndexMask( GLuint mask ) { GET_CURRENT_CONTEXT(ctx); if (ctx->Color.IndexMask == mask) return; FLUSH_VERTICES(ctx, _NEW_COLOR); ctx->Color.IndexMask = mask; } /** * Enable or disable writing of frame buffer color components. * * \param red whether to mask writing of the red color component. * \param green whether to mask writing of the green color component. * \param blue whether to mask writing of the blue color component. * \param alpha whether to mask writing of the alpha color component. * * \sa glColorMask(). * * Sets the appropriate value of gl_colorbuffer_attrib::ColorMask. On a * change, flushes the vertices and notifies the driver via the * dd_function_table::ColorMask callback. */ void GLAPIENTRY _mesa_ColorMask( GLboolean red, GLboolean green, GLboolean blue, GLboolean alpha ) { GET_CURRENT_CONTEXT(ctx); GLubyte tmp[4]; GLuint i; GLboolean flushed; if (MESA_VERBOSE & VERBOSE_API) _mesa_debug(ctx, "glColorMask(%d, %d, %d, %d)\n", red, green, blue, alpha); /* Shouldn't have any information about channel depth in core mesa * -- should probably store these as the native booleans: */ tmp[RCOMP] = red ? 0xff : 0x0; tmp[GCOMP] = green ? 0xff : 0x0; tmp[BCOMP] = blue ? 0xff : 0x0; tmp[ACOMP] = alpha ? 0xff : 0x0; flushed = GL_FALSE; for (i = 0; i < ctx->Const.MaxDrawBuffers; i++) { if (!TEST_EQ_4V(tmp, ctx->Color.ColorMask[i])) { if (!flushed) { FLUSH_VERTICES(ctx, _NEW_COLOR); } flushed = GL_TRUE; COPY_4UBV(ctx->Color.ColorMask[i], tmp); } } if (ctx->Driver.ColorMask) ctx->Driver.ColorMask( ctx, red, green, blue, alpha ); } /** * For GL_EXT_draw_buffers2 and GL3 */ void GLAPIENTRY _mesa_ColorMaski( GLuint buf, GLboolean red, GLboolean green, GLboolean blue, GLboolean alpha ) { GLubyte tmp[4]; GET_CURRENT_CONTEXT(ctx); if (MESA_VERBOSE & VERBOSE_API) _mesa_debug(ctx, "glColorMaskIndexed %u %d %d %d %d\n", buf, red, green, blue, alpha); if (buf >= ctx->Const.MaxDrawBuffers) { _mesa_error(ctx, GL_INVALID_VALUE, "glColorMaskIndexed(buf=%u)", buf); return; } /* Shouldn't have any information about channel depth in core mesa * -- should probably store these as the native booleans: */ tmp[RCOMP] = red ? 0xff : 0x0; tmp[GCOMP] = green ? 0xff : 0x0; tmp[BCOMP] = blue ? 0xff : 0x0; tmp[ACOMP] = alpha ? 0xff : 0x0; if (TEST_EQ_4V(tmp, ctx->Color.ColorMask[buf])) return; FLUSH_VERTICES(ctx, _NEW_COLOR); COPY_4UBV(ctx->Color.ColorMask[buf], tmp); if (ctx->Driver.ColorMaskIndexed) ctx->Driver.ColorMaskIndexed(ctx, buf, red, green, blue, alpha); } void GLAPIENTRY _mesa_ClampColor(GLenum target, GLenum clamp) { GET_CURRENT_CONTEXT(ctx); if (clamp != GL_TRUE && clamp != GL_FALSE && clamp != GL_FIXED_ONLY_ARB) { _mesa_error(ctx, GL_INVALID_ENUM, "glClampColorARB(clamp)"); return; } switch (target) { case GL_CLAMP_VERTEX_COLOR_ARB: if (ctx->API == API_OPENGL_CORE && !ctx->Extensions.ARB_color_buffer_float) { goto invalid_enum; } FLUSH_VERTICES(ctx, _NEW_LIGHT); ctx->Light.ClampVertexColor = clamp; _mesa_update_clamp_vertex_color(ctx); break; case GL_CLAMP_FRAGMENT_COLOR_ARB: if (ctx->API == API_OPENGL_CORE && !ctx->Extensions.ARB_color_buffer_float) { goto invalid_enum; } FLUSH_VERTICES(ctx, _NEW_FRAG_CLAMP); ctx->Color.ClampFragmentColor = clamp; _mesa_update_clamp_fragment_color(ctx); break; case GL_CLAMP_READ_COLOR_ARB: ctx->Color.ClampReadColor = clamp; break; default: goto invalid_enum; } return; invalid_enum: _mesa_error(ctx, GL_INVALID_ENUM, "glClampColor(%s)", _mesa_lookup_enum_by_nr(target)); } static GLboolean get_clamp_color(const struct gl_framebuffer *fb, GLenum clamp) { if (clamp == GL_TRUE || clamp == GL_FALSE) return clamp; ASSERT(clamp == GL_FIXED_ONLY); if (!fb) return GL_TRUE; return fb->_AllColorBuffersFixedPoint; } GLboolean _mesa_get_clamp_fragment_color(const struct gl_context *ctx) { return get_clamp_color(ctx->DrawBuffer, ctx->Color.ClampFragmentColor); } GLboolean _mesa_get_clamp_vertex_color(const struct gl_context *ctx) { return get_clamp_color(ctx->DrawBuffer, ctx->Light.ClampVertexColor); } GLboolean _mesa_get_clamp_read_color(const struct gl_context *ctx) { return get_clamp_color(ctx->ReadBuffer, ctx->Color.ClampReadColor); } /** * Update the ctx->Color._ClampFragmentColor field */ void _mesa_update_clamp_fragment_color(struct gl_context *ctx) { struct gl_framebuffer *fb = ctx->DrawBuffer; /* Don't clamp if: * - there is no colorbuffer * - all colorbuffers are unsigned normalized, so clamping has no effect * - there is an integer colorbuffer */ if (!fb || !fb->_HasSNormOrFloatColorBuffer || fb->_IntegerColor) ctx->Color._ClampFragmentColor = GL_FALSE; else ctx->Color._ClampFragmentColor = _mesa_get_clamp_fragment_color(ctx); } /** * Update the ctx->Color._ClampVertexColor field */ void _mesa_update_clamp_vertex_color(struct gl_context *ctx) { ctx->Light._ClampVertexColor = _mesa_get_clamp_vertex_color(ctx); } /** * Returns an appropriate gl_format for color rendering based on the * GL_FRAMEBUFFER_SRGB state. * * Some drivers implement GL_FRAMEBUFFER_SRGB using a flag on the blend state * (which GL_FRAMEBUFFER_SRGB maps to reasonably), but some have to do so by * overriding the format of the surface. This is a helper for doing the * surface format override variant. */ gl_format _mesa_get_render_format(const struct gl_context *ctx, gl_format format) { if (ctx->Color.sRGBEnabled) return format; else return _mesa_get_srgb_format_linear(format); } /**********************************************************************/ /** \name Initialization */ /*@{*/ /** * Initialization of the context's Color attribute group. * * \param ctx GL context. * * Initializes the related fields in the context color attribute group, * __struct gl_contextRec::Color. */ void _mesa_init_color( struct gl_context * ctx ) { GLuint i; /* Color buffer group */ ctx->Color.IndexMask = ~0u; memset(ctx->Color.ColorMask, 0xff, sizeof(ctx->Color.ColorMask)); ctx->Color.ClearIndex = 0; ASSIGN_4V( ctx->Color.ClearColor.f, 0, 0, 0, 0 ); ctx->Color.AlphaEnabled = GL_FALSE; ctx->Color.AlphaFunc = GL_ALWAYS; ctx->Color.AlphaRef = 0; ctx->Color.BlendEnabled = 0x0; for (i = 0; i < Elements(ctx->Color.Blend); i++) { ctx->Color.Blend[i].SrcRGB = GL_ONE; ctx->Color.Blend[i].DstRGB = GL_ZERO; ctx->Color.Blend[i].SrcA = GL_ONE; ctx->Color.Blend[i].DstA = GL_ZERO; ctx->Color.Blend[i].EquationRGB = GL_FUNC_ADD; ctx->Color.Blend[i].EquationA = GL_FUNC_ADD; } ASSIGN_4V( ctx->Color.BlendColor, 0.0, 0.0, 0.0, 0.0 ); ASSIGN_4V( ctx->Color.BlendColorUnclamped, 0.0, 0.0, 0.0, 0.0 ); ctx->Color.IndexLogicOpEnabled = GL_FALSE; ctx->Color.ColorLogicOpEnabled = GL_FALSE; ctx->Color.LogicOp = GL_COPY; ctx->Color.DitherFlag = GL_TRUE; if (ctx->Visual.doubleBufferMode) { ctx->Color.DrawBuffer[0] = GL_BACK; } else { ctx->Color.DrawBuffer[0] = GL_FRONT; } ctx->Color.ClampFragmentColor = ctx->API == API_OPENGL_COMPAT ? GL_FIXED_ONLY_ARB : GL_FALSE; ctx->Color._ClampFragmentColor = GL_FALSE; ctx->Color.ClampReadColor = GL_FIXED_ONLY_ARB; if (ctx->API == API_OPENGLES2) { /* GLES 3 behaves as though GL_FRAMEBUFFER_SRGB is always enabled. */ ctx->Color.sRGBEnabled = GL_TRUE; } else { ctx->Color.sRGBEnabled = GL_FALSE; } } /*@}*/