My orthographic matrix doesn't seem to be properly translating/scaling the pixels on my screen.
Here is how it is built:
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| public static Matrix4f orthographicMatrix(float near, float far) { float width = Display.getWidth(); float height = Display.getHeight(); return orthographicMatrix(width, height, near, far); } public static Matrix4f orthographicMatrix(float width, float height, float near, float far) { return orthographicMatrix(0, width, height, 0, near, far); } public static Matrix4f orthographicMatrix(float left, float right, float bottom, float top, float near, float far) { Matrix4f mat = new Matrix4f(); mat.m00 = 2 / (right - left); mat.m11 = 2 / (top - bottom); mat.m22 = -2 / (far - near); mat.m03 = -1 * ((right + left) / (right - left)); mat.m13 = -1 * ((top + bottom) / (top - bottom)); mat.m23 = -1 * ((far + near) / (far - near)); return mat; } |
Here's where I create a new one:
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| ortho = Matrix4f.orthographicMatrix(1, -1); |
Here's how it's sent to the vertex shader:
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| program.setUniformMatrix4("ortho", ortho); |
And here's the vertex shader:
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| # version 330
uniform mat4 ortho;
in vec3 vert;
void main() { gl_Position = ortho * vec4(vert, 1); } |
When I pass in 2 vectors (0, 0, 0) and (100f, 100f, 0) and draw them as points, this is what I get:

The screen size for that is 800x600. It seems that the x and y directions reversed as intended, but the origin is still in the center. I can't find what it is that I missed though for that too happen.
The calculated matrix is the same as one that I calculated by hand. So, I feel that I have the wrong expressions to compute the orthographic matrix. Though, I've verified from several locations that this is how you calculate it.