The magic RenderPixels function.

[ipdf/code.git] / src / screen.cpp

diff --git a/src/screen.cpp b/src/screen.cpp
index 5bca554..b5b6882 100644 (file)
--- a/src/screen.cpp
+++ b/src/screen.cpp
@@ -218,6 +218,47 @@ double Screen::GetLastFrameTimeGPU() const
        return frame_time_ns/1000000000.0;
 }
 
+void Screen::RenderPixels(int x, int y, int w, int h, void *pixels) const
+{
+       GLenum texture_format = GL_RGBA;
+
+       m_texture_prog.Use();
+       GraphicsBuffer quad_vertex_buffer;
+       quad_vertex_buffer.SetUsage(GraphicsBuffer::BufferUsageStaticDraw);
+       quad_vertex_buffer.SetType(GraphicsBuffer::BufferTypeVertex);
+       GLfloat quad[] = { 
+               0, 0, (float)x, (float)y,
+               1, 0, (float)(x+w), y,
+               1, 1, (float)(x+w), (float)(y+h),
+               0, 1, (float)x, (float)(y+h)
+       };
+       quad_vertex_buffer.Upload(sizeof(GLfloat) * 16, quad);
+       quad_vertex_buffer.Bind();
+       m_viewport_ubo.Bind();
+
+       glUniform4f(m_colour_uniform_location, 1.0f, 1.0f, 1.0f, 1.0f);
+
+       GLuint texID;
+       glGenTextures(1, &texID);
+       glBindTexture(GL_TEXTURE_2D, texID);
+
+       glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
+       glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
+       glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
+       glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
+
+       glTexImage2D(GL_TEXTURE_2D, 0, 4, w, h, 0, texture_format, GL_UNSIGNED_BYTE, pixels);
+
+       glEnableVertexAttribArray(0);
+       glEnableVertexAttribArray(1);
+       glVertexAttribPointer(0, 2, GL_FLOAT, GL_FALSE, 4*sizeof(float), (void*)(2*sizeof(float)));
+       glVertexAttribPointer(1, 2, GL_FLOAT, GL_FALSE, 4*sizeof(float), 0);
+       glDisableVertexAttribArray(1);
+       glDisableVertexAttribArray(0);
+       glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
+
+}
+
 void Screen::ScreenShot(const char * filename) const
 {
        Debug("Attempting to save BMP to file %s", filename);