1
2/*
3 * Copyright 2011 Google Inc.
4 *
5 * Use of this source code is governed by a BSD-style license that can be
6 * found in the LICENSE file.
7 */
8
9#include <GL/osmesa.h>
10
11#include "gl/SkMesaGLContext.h"
12#include "gl/GrGLDefines.h"
13
14SkMesaGLContext::AutoContextRestore::AutoContextRestore() {
15    fOldContext = (Context)OSMesaGetCurrentContext();
16    if (NULL != (OSMesaContext)fOldContext) {
17        OSMesaGetColorBuffer((OSMesaContext)fOldContext,
18                              &fOldWidth, &fOldHeight,
19                              &fOldFormat, &fOldImage);
20    }
21}
22
23SkMesaGLContext::AutoContextRestore::~AutoContextRestore() {
24    if (NULL != (OSMesaContext)fOldContext) {
25        OSMesaMakeCurrent((OSMesaContext)fOldContext, fOldImage,
26                          fOldFormat, fOldWidth, fOldHeight);
27    }
28}
29
30///////////////////////////////////////////////////////////////////////////////
31
32SkMesaGLContext::SkMesaGLContext()
33    : fContext(static_cast<Context>(NULL))
34    , fImage(NULL) {
35    GR_STATIC_ASSERT(sizeof(Context) == sizeof(OSMesaContext));
36}
37
38SkMesaGLContext::~SkMesaGLContext() {
39    this->destroyGLContext();
40}
41
42void SkMesaGLContext::destroyGLContext() {
43    if (fImage) {
44        sk_free(fImage);
45        fImage = NULL;
46    }
47
48    if (fContext) {
49        OSMesaDestroyContext((OSMesaContext)fContext);
50        fContext = static_cast<Context>(NULL);
51    }
52}
53
54static const GrGLint gBOGUS_SIZE = 16;
55
56const GrGLInterface* SkMesaGLContext::createGLContext() {
57    /* Create an RGBA-mode context */
58#if OSMESA_MAJOR_VERSION * 100 + OSMESA_MINOR_VERSION >= 305
59    /* specify Z, stencil, accum sizes */
60    fContext = (Context)OSMesaCreateContextExt(OSMESA_BGRA, 0, 0, 0, NULL);
61#else
62    fContext = (Context)OSMesaCreateContext(OSMESA_BGRA, NULL);
63#endif
64    if (!fContext) {
65        SkDebugf("OSMesaCreateContext failed!\n");
66        this->destroyGLContext();
67        return NULL;
68    }
69    // Allocate the image buffer
70    fImage = (GrGLubyte *) sk_malloc_throw(gBOGUS_SIZE * gBOGUS_SIZE *
71                                           4 * sizeof(GrGLubyte));
72    if (!fImage) {
73        SkDebugf("Alloc image buffer failed!\n");
74        this->destroyGLContext();
75        return NULL;
76    }
77
78    // Bind the buffer to the context and make it current
79    if (!OSMesaMakeCurrent((OSMesaContext)fContext,
80                           fImage,
81                           GR_GL_UNSIGNED_BYTE,
82                           gBOGUS_SIZE,
83                           gBOGUS_SIZE)) {
84        SkDebugf("OSMesaMakeCurrent failed!\n");
85        this->destroyGLContext();
86        return NULL;
87    }
88
89    const GrGLInterface* interface = GrGLCreateMesaInterface();
90    if (!interface) {
91        SkDebugf("Could not create GL interface!\n");
92        this->destroyGLContext();
93        return NULL;
94    }
95    return interface;
96
97}
98
99void SkMesaGLContext::makeCurrent() const {
100    if (fContext) {
101        if (!OSMesaMakeCurrent((OSMesaContext)fContext, fImage,
102                               GR_GL_UNSIGNED_BYTE, gBOGUS_SIZE, gBOGUS_SIZE)) {
103            SkDebugf("Could not make MESA context current.");
104        }
105    }
106}
107
108void SkMesaGLContext::swapBuffers() const { }
109