[NEW] Added mat4_ortho_projection2

- This orthographic projection matrix doesn't swap the widths and heights internally.
ravi688 · Jul 30, 2024 · ec3a2ce · ec3a2ce
1 parent 28bba22
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diff --git a/include/hpml/affine_transformation.h b/include/hpml/affine_transformation.h
@@ -23,6 +23,8 @@ HPML_API mat4_t mat4_rotation(float x, float y, float z);
  */
 HPML_API mat4_t mat4_ortho_projection(float nearClipPlane, float farClipPlane, float height, float aspectRatio);
 
+HPML_API mat4_t mat4_ortho_projection2(float nearClipPlane, float farClipPlane, float height, float aspectRatio);
+
 /* mat4_persp_projection: Creates a perspective projection matrix
  * nearClipPlane: position of the near clip plane relative to the camera, +ve means front and -ve means back
  * farClipPlane: position of the far clip plane relative to the camera, +ve means front and -ve means back

diff --git a/source/affine_transformation.c b/source/affine_transformation.c
@@ -40,6 +40,30 @@ EXCEPTION_BLOCK
 	};
 }
 
+HPML_API mat4_t mat4_ortho_projection2(float nearClipPlane, float farClipPlane, float height, float aspectRatio)
+{
+	float box_x = farClipPlane - nearClipPlane;
+	float box_y;
+	float box_z;
+		box_y = height;
+		box_z = aspectRatio * height;
+EXCEPTION_BLOCK
+(
+	if((box_x == 0) || (box_y == 0) || (box_z == 0))
+		throw_exception(DIVIDE_BY_ZERO);
+	if((box_x < 0) || (box_y < 0) || (box_z < 0))
+		throw_exception(NEGATIVE_VALUE);
+)
+	float t = 1 / box_x;
+	return (mat4_t)
+	{
+		0, 0, 2 / box_z, 0,
+		0, 2 / box_y, 0, 0,
+		t, 0, 0, - nearClipPlane * t,
+		0, 0, 0, 1
+	};
+}
+
 HPML_API mat4_t mat4_persp_projection(float nearClipPlane, float farClipPlane, float fieldOfView, float aspectRatio)
 {
 EXCEPTION_BLOCK