Merge pull request #288 from openscad/issue11_2

Issue11 2

1 files changed, 73 insertions, 0 deletions

diff --git a/src/OffscreenContextAll.hpp b/src/OffscreenContextAll.hpp
new file mode 100644
index 0000000..b845114
--- /dev/null
+++ b/src/OffscreenContextAll.hpp
@@ -0,0 +1,73 @@
+// Functions shared by OffscreenContext[platform].cc
+// #include this directly after definition of struct OffscreenContext.
+
+#include <vector>
+#include <ostream>
+
+void bind_offscreen_context(OffscreenContext *ctx)
+{
+	if (ctx) fbo_bind(ctx->fbo);
+}
+
+/*
+   Capture framebuffer from OpenGL and write it to the given filename as PNG.
+ */
+bool save_framebuffer(OffscreenContext *ctx, const char *filename)
+{
+	std::ofstream fstream(filename,std::ios::out|std::ios::binary);
+	if (!fstream.is_open()) {
+		std::cerr << "Can't open file " << filename << " for writing";
+		return false;
+	} else {
+		save_framebuffer(ctx, fstream);
+		fstream.close();
+	}
+	return true;
+}
+
+/*!
+  Capture framebuffer from OpenGL and write it to the given ostream.
+  Called by save_framebuffer() from platform-specific code.
+ */
+bool save_framebuffer_common(OffscreenContext *ctx, std::ostream &output)
+{
+	if (!ctx) return false;
+	int samplesPerPixel = 4; // R, G, B and A
+	std::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(output, flippedBuffer, ctx->width, ctx->height);
+
+	free(flippedBuffer);
+
+	return writeok;
+}
+
+//	Called by create_offscreen_context() from platform-specific code.
+OffscreenContext *create_offscreen_context_common(OffscreenContext *ctx)
+{
+	if (!ctx) return NULL;
+	GLenum err = glewInit(); // must come after Context creation and before FBO c$
+	if (GLEW_OK != err) {
+		std::cerr << "Unable to init GLEW: " << glewGetErrorString(err) << "\n";
+		return NULL;
+	}
+
+	ctx->fbo = fbo_new();
+	if (!fbo_init(ctx->fbo, ctx->width, ctx->height)) {
+		return NULL;
+	}
+
+	return ctx;
+}
+