diff --git a/cogl/cogl-pipeline-glsl.c b/cogl/cogl-pipeline-glsl.c index 6db16446e..f187dd8ff 100644 --- a/cogl/cogl-pipeline-glsl.c +++ b/cogl/cogl-pipeline-glsl.c @@ -61,6 +61,7 @@ #define glDeleteShader ctx->drv.pf_glDeleteShader #define glGetUniformLocation ctx->drv.pf_glGetUniformLocation #define glUniform1i ctx->drv.pf_glUniform1i +#define glUniform1f ctx->drv.pf_glUniform1f #define glUniform4fv ctx->drv.pf_glUniform4fv #endif /* HAVE_COGL_GLES2 */ @@ -117,6 +118,12 @@ typedef struct _GlslProgramState custom uniforms. This is a massive hack but it can go away once this GLSL backend starts generating its own shaders */ GLuint gles2_program; + + /* Under GLES2 the alpha test is implemented in the shader. We need + a uniform for the reference value */ + gboolean alpha_test_reference_used; + gboolean dirty_alpha_test_reference; + GLint alpha_test_reference_uniform; #endif /* We need to track the last pipeline that the program was used with @@ -416,6 +423,12 @@ _cogl_pipeline_backend_glsl_start (CoglPipeline *pipeline, "main ()\n" "{\n"); +#ifdef HAVE_COGL_GLES2 + priv->glsl_program_state->alpha_test_reference_uniform = -1; + priv->glsl_program_state->alpha_test_reference_used = FALSE; + priv->glsl_program_state->dirty_alpha_test_reference = FALSE; +#endif + for (i = 0; i < n_layers; i++) { priv->glsl_program_state->unit_state[i].sampled = FALSE; @@ -878,6 +891,103 @@ update_constants_cb (CoglPipeline *pipeline, return TRUE; } +/* GLES2 doesn't have alpha testing so we need to implement it in the + shader */ + +#ifdef HAVE_COGL_GLES2 + +static void +add_alpha_test_snippet (CoglPipeline *pipeline, + GlslProgramState *glsl_program_state) +{ + CoglPipelineAlphaFunc alpha_func; + + alpha_func = cogl_pipeline_get_alpha_test_function (pipeline); + + if (alpha_func == COGL_PIPELINE_ALPHA_FUNC_ALWAYS) + /* Do nothing */ + return; + + if (alpha_func == COGL_PIPELINE_ALPHA_FUNC_NEVER) + { + /* Always discard the fragment */ + g_string_append (glsl_program_state->source, + " discard;\n"); + return; + } + + /* For all of the other alpha functions we need a uniform for the + reference */ + + glsl_program_state->alpha_test_reference_used = TRUE; + glsl_program_state->dirty_alpha_test_reference = TRUE; + + g_string_append (glsl_program_state->header, + "uniform float _cogl_alpha_test_ref;\n"); + + g_string_append (glsl_program_state->source, + " if (cogl_color_out.a "); + + switch (alpha_func) + { + case COGL_PIPELINE_ALPHA_FUNC_LESS: + g_string_append (glsl_program_state->source, ">="); + break; + case COGL_PIPELINE_ALPHA_FUNC_EQUAL: + g_string_append (glsl_program_state->source, "!="); + break; + case COGL_PIPELINE_ALPHA_FUNC_LEQUAL: + g_string_append (glsl_program_state->source, ">"); + break; + case COGL_PIPELINE_ALPHA_FUNC_GREATER: + g_string_append (glsl_program_state->source, "<="); + break; + case COGL_PIPELINE_ALPHA_FUNC_NOTEQUAL: + g_string_append (glsl_program_state->source, "=="); + break; + case COGL_PIPELINE_ALPHA_FUNC_GEQUAL: + g_string_append (glsl_program_state->source, "< "); + break; + + case COGL_PIPELINE_ALPHA_FUNC_ALWAYS: + case COGL_PIPELINE_ALPHA_FUNC_NEVER: + g_assert_not_reached (); + break; + } + + g_string_append (glsl_program_state->source, + " _cogl_alpha_test_ref)\n discard;\n"); +} + +static void +update_alpha_test_reference (CoglPipeline *pipeline, + GLuint gl_program, + GlslProgramState *glsl_program_state) +{ + float alpha_reference; + + if (glsl_program_state->dirty_alpha_test_reference) + { + if (glsl_program_state->alpha_test_reference_uniform == -1) + { + GE_RET( glsl_program_state->alpha_test_reference_uniform, + glGetUniformLocation (gl_program, + "_cogl_alpha_test_ref") ); + g_return_if_fail (glsl_program_state-> + alpha_test_reference_uniform != -1); + } + + alpha_reference = cogl_pipeline_get_alpha_test_reference (pipeline); + + GE( glUniform1f (glsl_program_state->alpha_test_reference_uniform, + alpha_reference) ); + + glsl_program_state->dirty_alpha_test_reference = FALSE; + } +} + +#endif /* HAVE_COGL_GLES2 */ + gboolean _cogl_pipeline_backend_glsl_end (CoglPipeline *pipeline, unsigned long pipelines_difference) @@ -934,6 +1044,10 @@ _cogl_pipeline_backend_glsl_end (CoglPipeline *pipeline, 0 /* no application private data */); COGL_COUNTER_INC (_cogl_uprof_context, backend_glsl_compile_counter); +#ifdef HAVE_COGL_GLES2 + add_alpha_test_snippet (pipeline, glsl_program_state); +#endif + g_string_append (glsl_program_state->source, "}\n"); if (G_UNLIKELY (cogl_debug_flags & COGL_DEBUG_SHOW_SOURCE)) @@ -1016,6 +1130,19 @@ _cogl_pipeline_backend_glsl_end (CoglPipeline *pipeline, update_constants_cb, &state); +#ifdef HAVE_COGL_GLES2 + if (glsl_program_state->alpha_test_reference_used) + { + if (gl_program_changed) + glsl_program_state->alpha_test_reference_uniform = -1; + if (gl_program_changed || + glsl_program_state->last_used_for_pipeline != pipeline) + glsl_program_state->dirty_alpha_test_reference = TRUE; + + update_alpha_test_reference (pipeline, gl_program, glsl_program_state); + } +#endif + if (user_program) _cogl_program_flush_uniforms (user_program, gl_program, @@ -1035,13 +1162,22 @@ _cogl_pipeline_backend_glsl_pre_change_notify (CoglPipeline *pipeline, { static const unsigned long fragment_op_changes = COGL_PIPELINE_STATE_LAYERS | +#ifdef COGL_HAS_GLES2 + COGL_PIPELINE_STATE_ALPHA_FUNC | +#endif COGL_PIPELINE_STATE_USER_SHADER; /* TODO: COGL_PIPELINE_STATE_FOG */ - if (!(change & fragment_op_changes)) - return; - - dirty_glsl_program_state (pipeline); + if ((change & fragment_op_changes)) + dirty_glsl_program_state (pipeline); +#ifdef COGL_HAS_GLES2 + else if ((change & COGL_PIPELINE_STATE_ALPHA_FUNC_REFERENCE)) + { + GlslProgramState *glsl_program_state = + get_glsl_program_state (pipeline); + glsl_program_state->dirty_alpha_test_reference = TRUE; + } +#endif } /* NB: layers are considered immutable once they have any dependants