diff options
| -rw-r--r-- | src/mesa/main/buffers.c | 23 |
1 files changed, 19 insertions, 4 deletions
diff --git a/src/mesa/main/buffers.c b/src/mesa/main/buffers.c index 3dcd46f0180..b4f324c6c91 100644 --- a/src/mesa/main/buffers.c +++ b/src/mesa/main/buffers.c @@ -94,7 +94,7 @@ supported_buffer_bitmask(const struct gl_context *ctx, * GL_FRONT_AND_BACK), return the corresponding bitmask of BUFFER_BIT_* flags. */ static GLbitfield -draw_buffer_enum_to_bitmask(GLenum buffer) +draw_buffer_enum_to_bitmask(const struct gl_context *ctx, GLenum buffer) { switch (buffer) { case GL_NONE: @@ -102,6 +102,21 @@ draw_buffer_enum_to_bitmask(GLenum buffer) case GL_FRONT: return BUFFER_BIT_FRONT_LEFT | BUFFER_BIT_FRONT_RIGHT; case GL_BACK: + if (_mesa_is_gles3(ctx)) { + /* Page 181 (page 192 of the PDF) in section 4.2.1 of the OpenGL + * ES 3.0.1 specification says: + * + * "When draw buffer zero is BACK, color values are written + * into the sole buffer for single-buffered contexts, or into + * the back buffer for double-buffered contexts." + * + * Since there is no stereo rendering in ES 3.0, only return the + * LEFT bits. This also satisfies the "n must be 1" requirement. + */ + if (ctx->DrawBuffer->Visual.doubleBufferMode) + return BUFFER_BIT_BACK_LEFT; + return BUFFER_BIT_FRONT_LEFT; + } return BUFFER_BIT_BACK_LEFT | BUFFER_BIT_BACK_RIGHT; case GL_RIGHT: return BUFFER_BIT_FRONT_RIGHT | BUFFER_BIT_BACK_RIGHT; @@ -241,7 +256,7 @@ _mesa_DrawBuffer(GLenum buffer) else { const GLbitfield supportedMask = supported_buffer_bitmask(ctx, ctx->DrawBuffer); - destMask = draw_buffer_enum_to_bitmask(buffer); + destMask = draw_buffer_enum_to_bitmask(ctx, buffer); if (destMask == BAD_MASK) { /* totally bogus buffer */ _mesa_error(ctx, GL_INVALID_ENUM, @@ -321,7 +336,7 @@ _mesa_DrawBuffers(GLsizei n, const GLenum *buffers) return; } - destMask[output] = draw_buffer_enum_to_bitmask(buffers[output]); + destMask[output] = draw_buffer_enum_to_bitmask(ctx, buffers[output]); /* From the OpenGL 3.0 specification, page 258: * "Each buffer listed in bufs must be one of the values from tables @@ -451,7 +466,7 @@ _mesa_drawbuffers(struct gl_context *ctx, GLuint n, const GLenum *buffers, const GLbitfield supportedMask = supported_buffer_bitmask(ctx, fb); GLuint output; for (output = 0; output < n; output++) { - mask[output] = draw_buffer_enum_to_bitmask(buffers[output]); + mask[output] = draw_buffer_enum_to_bitmask(ctx, buffers[output]); ASSERT(mask[output] != BAD_MASK); mask[output] &= supportedMask; } |