1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
|
/*
Create an OpenGL context without creating an OpenGL Window. for Windows.
*/
#include <windows.h>
#include "OffscreenContext.h"
#include "printutils.h"
#include "imageutils.h"
#include "fbo.h"
#include <vector>
#include <GL/gl.h>
using namespace std;
struct OffscreenContext
{
HWND window;
HDC dev_context;
HGLRC openGLContext;
int width;
int height;
fbo_t *fbo;
};
void offscreen_context_init(OffscreenContext &ctx, int width, int height)
{
ctx.window = (HWND)NULL;
ctx.dev_context = (HDC)NULL;
ctx.openGLContext = (HGLRC)NULL;
ctx.width = width;
ctx.height = height;
ctx.fbo = NULL;
}
void glewCheck() {
#ifdef DEBUG
cerr << "GLEW version " << glewGetString(GLEW_VERSION) << "\n";
cerr << (const char *)glGetString(GL_RENDERER) << "(" << (const char *)glGetString(GL_VENDOR) << ")\n"
<< "OpenGL version " << (const char *)glGetString(GL_VERSION) << "\n";
cerr << "Extensions: " << (const char *)glGetString(GL_EXTENSIONS) << "\n";
if (GLEW_ARB_framebuffer_object) {
cerr << "ARB_FBO supported\n";
}
if (GLEW_EXT_framebuffer_object) {
cerr << "EXT_FBO supported\n";
}
if (GLEW_EXT_packed_depth_stencil) {
cerr << "EXT_packed_depth_stencil\n";
}
#endif
}
LRESULT CALLBACK WndProc(HWND hwnd, UINT message, WPARAM wparam, LPARAM lparam)
{
return DefWindowProc( hwnd, message, wparam, lparam );
}
bool create_wgl_dummy_context(OffscreenContext &ctx)
{
// create window
HINSTANCE inst = GetModuleHandle(0);
WNDCLASS wc;
ZeroMemory( &wc, sizeof( wc ) );
wc.style = CS_OWNDC;
wc.lpfnWndProc = WndProc;
wc.hInstance = inst;
wc.lpszClassName = "OpenSCAD";
RegisterClass( &wc );
HWND window = CreateWindow( "OpenSCAD", "OpenSCAD",
WS_CAPTION | WS_POPUPWINDOW | WS_VISIBLE,
0, 0, 256, 256, NULL, NULL, inst, NULL );
// create WGL context, make current
PIXELFORMATDESCRIPTOR pixformat;
int chosenformat;
HDC dev_context = GetDC( window );
ZeroMemory( &pixformat, sizeof( pixformat ) );
pixformat.nSize = sizeof( pixformat );
pixformat.nVersion = 1;
pixformat.dwFlags = PFD_DRAW_TO_WINDOW | PFD_SUPPORT_OPENGL;
pixformat.iPixelType = PFD_TYPE_RGBA;
pixformat.cColorBits = 24;
pixformat.cDepthBits = 16;
pixformat.iLayerType = PFD_MAIN_PLANE;
chosenformat = ChoosePixelFormat( dev_context, &pixformat );
SetPixelFormat( dev_context, chosenformat, &pixformat );
HGLRC gl_render_context = wglCreateContext( dev_context );
wglMakeCurrent( dev_context, gl_render_context );
return true;
}
OffscreenContext *create_offscreen_context(int w, int h)
{
OffscreenContext *ctx = new OffscreenContext;
offscreen_context_init( *ctx, w, h );
// before an FBO can be setup, a WGL context must be created
// this call alters ctx->window and ctx->openGLContext
// and ctx->dev_context if successfull
if (!create_wgl_dummy_context( *ctx )) {
return NULL;
}
glewInit(); //must come after Context creation and before FBO calls.
glewCheck();
ctx->fbo = fbo_new();
if (!fbo_init(ctx->fbo, w, h)) {
return NULL;
}
ctx = NULL;
return ctx;
}
bool teardown_offscreen_context(OffscreenContext *ctx)
{
if (ctx) {
wglMakeCurrent( NULL, NULL );
wglDeleteContext( ctx->openGLContext );
ReleaseDC( ctx->window, ctx->dev_context );
fbo_unbind(ctx->fbo);
fbo_delete(ctx->fbo);
return true;
}
return false;
}
/*!
Capture framebuffer from OpenGL and write it to the given filename as PNG.
*/
bool save_framebuffer(OffscreenContext *ctx, const char *filename)
{
if (!ctx || !filename) return false;
int samplesPerPixel = 4; // R, G, B and A
vector<GLubyte> pixels(ctx->width * ctx->height * samplesPerPixel);
glReadPixels(0, 0, ctx->width, ctx->height, GL_RGBA, GL_UNSIGNED_BYTE, &pixels[0]);
// Flip it vertically - images read from OpenGL buffers are upside-down
int rowBytes = samplesPerPixel * ctx->width;
unsigned char *flippedBuffer = (unsigned char *)malloc(rowBytes * ctx->height);
if (!flippedBuffer) {
std::cerr << "Unable to allocate flipped buffer for corrected image.";
return 1;
}
flip_image(&pixels[0], flippedBuffer, samplesPerPixel, ctx->width, ctx->height);
bool writeok = write_png(filename, flippedBuffer, ctx->width, ctx->height);
free(flippedBuffer);
return writeok;
}
void bind_offscreen_context(OffscreenContext *ctx)
{
if (ctx) fbo_bind(ctx->fbo);
}
|
