GPU Matrix API refactor: Stick to a single 4x4 stack for 2D and 3D

* Brings us closer to core profile, all matrices are working, and apart
from a problem with text drawing, Blender is working fine.

* Reduce the coding overhead of having to setup/teardown when
alternating between 2D and 3D drawing sessions.

* Gives us fewer modes and states we need to keep track of.

Unfortunatelly this also "rejects a fundamental change" the original
design was trying to make - that 2D is different from 3D and
deserves its own best implementation.

That said, it is still aligned with the function API design as
originally implemented (i.e., it still uses gpuTranslate2D, ...).

Finally, if you build with core profile and this patch you get:
https://developer.blender.org/F545352

[The text glitch is an unrelated issue].

Reviewers: merwin, sergey, brecht

Differential Revision: https://developer.blender.org/D2626

3 files changed, 78 insertions, 290 deletions

diff --git a/source/blender/gpu/GPU_matrix.h b/source/blender/gpu/GPU_matrix.h
index 62b5b7f8ba5..4a47f55a6c6 100644
--- a/source/blender/gpu/GPU_matrix.h
+++ b/source/blender/gpu/GPU_matrix.h
@@ -69,12 +69,6 @@ typedef enum {
 
 MatrixMode gpuMatrixMode(void);
 
-void gpuMatrixBegin2D(void);
-void gpuMatrixBegin3D(void);
-void gpuMatrixEnd(void);
-/* TODO: gpuMatrixResume2D & gpuMatrixResume3D to switch modes but not reset stack */
-
-
 /* ModelView Matrix (2D or 3D) */
 
 void gpuPushMatrix(void); /* TODO: PushCopy vs PushIdentity? */
@@ -105,12 +99,7 @@ void gpuLookAt(float eyeX, float eyeY, float eyeZ, float centerX, float centerY,
 
 /* 2D ModelView Matrix */
 
-#if MATRIX_2D_4x4
 void gpuMultMatrix2D(const float m[4][4]);
-#else
-void gpuLoadMatrix2D(const float m[3][3]);
-void gpuMultMatrix2D(const float m[3][3]);
-#endif
 
 void gpuTranslate2f(float x, float y);
 void gpuTranslate2fv(const float vec[2]);
@@ -187,12 +176,7 @@ bool gpuMatricesDirty(void); /* since last bind */
 
 #  define gpuLoadProjectionMatrix3D(x)  gpuLoadProjectionMatrix3D((const float (*)[4])(x))
 
-# if MATRIX_2D_4x4
 #  define gpuMultMatrix2D(x)  gpuMultMatrix2D((const float (*)[4])(x))
-# else
-#  define gpuMultMatrix2D(x)  gpuMultMatrix2D((const float (*)[3])(x))
-#  define gpuLoadMatrix2D(x)  gpuLoadMatrix2D((const float (*)[3])(x))
-# endif
 
 #  define gpuGetModelViewMatrix3D(x)  gpuGetModelViewMatrix3D((float (*)[4])(x))
 #  define gpuGetProjectionMatrix3D(x)  gpuGetProjectionMatrix3D((float (*)[4])(x))
diff --git a/source/blender/gpu/intern/gpu_framebuffer.c b/source/blender/gpu/intern/gpu_framebuffer.c
index 5e66c691f37..fc6eb6baf51 100644
--- a/source/blender/gpu/intern/gpu_framebuffer.c
+++ b/source/blender/gpu/intern/gpu_framebuffer.c
@@ -415,9 +415,6 @@ void GPU_framebuffer_blur(
 		
 	glDisable(GL_DEPTH_TEST);
 	
-	/* Load fresh matrices */
-	gpuMatrixBegin3D(); /* TODO: finish 2D API */
-
 	/* Blurring horizontally */
 	/* We do the bind ourselves rather than using GPU_framebuffer_texture_bind() to avoid
 	 * pushing unnecessary matrices onto the OpenGL stack. */
@@ -451,8 +448,6 @@ void GPU_framebuffer_blur(
 	Batch_Uniform2f(&batch, "ScaleU", scalev[0], scalev[1]);
 	Batch_Uniform1i(&batch, "textureSource", GL_TEXTURE0);
 	Batch_draw(&batch);
-
-	gpuMatrixEnd();
 }
 
 void GPU_framebuffer_blit(GPUFrameBuffer *fb_read, int read_slot, GPUFrameBuffer *fb_write, int write_slot, bool use_depth)
diff --git a/source/blender/gpu/intern/gpu_matrix.c b/source/blender/gpu/intern/gpu_matrix.c
index 186e14e825f..8b58a981a65 100644
--- a/source/blender/gpu/intern/gpu_matrix.c
+++ b/source/blender/gpu/intern/gpu_matrix.c
@@ -48,15 +48,6 @@ typedef struct {
 	Mat4 ModelViewStack3D[MATRIX_STACK_DEPTH];
 	Mat4 ProjectionMatrix3D;
 
-#if MATRIX_2D_4x4
-	Mat4 ModelViewStack2D[MATRIX_STACK_DEPTH];
-	Mat4 ProjectionMatrix2D;
-#else
-	Mat3 ModelViewStack2D[MATRIX_STACK_DEPTH];
-	Mat3 ProjectionMatrix2D;
-#endif
-
-	MatrixMode mode;
 	unsigned top; /* of current stack (would have to replicate if gpuResume2D/3D are implemented) */
 
 	bool dirty;
@@ -69,55 +60,33 @@ typedef struct {
 	 */
 } MatrixState;
 
-static MatrixState state; /* TODO(merwin): make part of GPUContext, alongside immediate mode & state tracker */
+#define MATRIX_4X4_IDENTITY {{1.0f, 0.0f, 0.0f, 0.0f}, \
+                             {0.0f, 1.0f, 0.0f, 0.0f}, \
+                             {0.0f, 0.0f, 1.0f, 0.0f}, \
+                             {0.0f, 0.0f, 0.0f, 1.0f}}
+
+/* TODO(merwin): make part of GPUContext, alongside immediate mode & state tracker */
+static MatrixState state = {
+	.ModelViewStack3D = {MATRIX_4X4_IDENTITY},
+	.ProjectionMatrix3D = MATRIX_4X4_IDENTITY,
+};
+
+#undef MATRIX_4X4_IDENTITY
 
 #define ModelView3D state.ModelViewStack3D[state.top]
-#define ModelView2D state.ModelViewStack2D[state.top]
 #define Projection3D state.ProjectionMatrix3D
-#define Projection2D state.ProjectionMatrix2D
 
 void gpuMatrixInit(void)
 {
 	memset(&state, 0, sizeof(MatrixState));
 }
 
-void gpuMatrixBegin2D(void)
-{
-	state.mode = MATRIX_MODE_2D;
-	state.top = 0;
-#if MATRIX_2D_4x4
-	unit_m4(ModelView2D);
-	unit_m4(Projection2D);
-#else
-	unit_m3(ModelView2D);
-	unit_m3(Projection2D);
-#endif
-}
-
-void gpuMatrixBegin3D(void)
-{
-	state.mode = MATRIX_MODE_3D;
-	state.top = 0;
-	unit_m4(ModelView3D);
-	unit_m4(Projection3D);
-}
-
-void gpuMatrixEnd(void)
-{
-	state.mode = MATRIX_MODE_INACTIVE;
-}
-
-
 #ifdef WITH_GPU_SAFETY
 
 /* Check if matrix is numerically good */
 static void checkmat(cosnt float *m)
 {
-#if MATRIX_2D_4x4
 	const int n = 16;
-#else
-	const int n = state.mode == MATRIX_MODE_3D ? 16 : 9;
-#endif
 	for (int i = 0; i < n; i++) {
 #if _MSC_VER
 		BLI_assert(_finite(m[i]));
@@ -139,37 +108,28 @@ static void checkmat(cosnt float *m)
 void gpuPushMatrix(void)
 {
 #if SUPPORT_LEGACY_MATRIX
-	if (state.mode == MATRIX_MODE_INACTIVE) {
+	{
 		glPushMatrix();
 		state.dirty = true;
 		return;
 	}
 #endif
 
-	BLI_assert(state.mode != MATRIX_MODE_INACTIVE);
 	BLI_assert(state.top < MATRIX_STACK_DEPTH);
 	state.top++;
-	if (state.mode == MATRIX_MODE_3D)
-		copy_m4_m4(ModelView3D, state.ModelViewStack3D[state.top - 1]);
-	else
-#if MATRIX_2D_4x4
-		copy_m4_m4(ModelView2D, state.ModelViewStack2D[state.top - 1]);
-#else
-		copy_m3_m3(ModelView2D, state.ModelViewStack2D[state.top - 1]);
-#endif
+	copy_m4_m4(ModelView3D, state.ModelViewStack3D[state.top - 1]);
 }
 
 void gpuPopMatrix(void)
 {
 #if SUPPORT_LEGACY_MATRIX
-	if (state.mode == MATRIX_MODE_INACTIVE) {
+	{
 		glPopMatrix();
 		state.dirty = true;
 		return;
 	}
 #endif
 
-	BLI_assert(state.mode != MATRIX_MODE_INACTIVE);
 	BLI_assert(state.top > 0);
 	state.top--;
 	state.dirty = true;
@@ -178,14 +138,13 @@ void gpuPopMatrix(void)
 void gpuLoadMatrix3D(const float m[4][4])
 {
 #if SUPPORT_LEGACY_MATRIX
-	if (state.mode == MATRIX_MODE_INACTIVE) {
+	{
 		glLoadMatrixf((const float*) m);
 		state.dirty = true;
 		return;
 	}
 #endif
 
-	BLI_assert(state.mode == MATRIX_MODE_3D);
 	copy_m4_m4(ModelView3D, m);
 	CHECKMAT(ModelView3D);
 	state.dirty = true;
@@ -194,7 +153,7 @@ void gpuLoadMatrix3D(const float m[4][4])
 void gpuLoadProjectionMatrix3D(const float m[4][4])
 {
 #if SUPPORT_LEGACY_MATRIX
-	if (state.mode == MATRIX_MODE_INACTIVE) {
+	{
 		GLenum mode;
 		glGetIntegerv(GL_MATRIX_MODE, (GLint*)&mode);
 		if (mode != GL_PROJECTION) {
@@ -212,7 +171,6 @@ void gpuLoadProjectionMatrix3D(const float m[4][4])
 	}
 #endif
 
-	BLI_assert(state.mode == MATRIX_MODE_3D);
 	copy_m4_m4(Projection3D, m);
 	CHECKMAT(Projection3D);
 	state.dirty = true;
@@ -221,7 +179,6 @@ void gpuLoadProjectionMatrix3D(const float m[4][4])
 #if 0 /* unused at the moment */
 void gpuLoadMatrix2D(const float m[3][3])
 {
-	BLI_assert(state.mode == MATRIX_MODE_2D);
 	copy_m3_m3(ModelView2D, m);
 	CHECKMAT(ModelView2D);
 	state.dirty = true;
@@ -230,49 +187,27 @@ void gpuLoadMatrix2D(const float m[3][3])
 
 void gpuLoadIdentity(void)
 {
-	switch (state.mode) {
-		case MATRIX_MODE_3D:
-			unit_m4(ModelView3D);
-			break;
-		case MATRIX_MODE_2D:
-#if MATRIX_2D_4x4
-			unit_m4(ModelView2D);
-#else
-			unit_m3(ModelView2D);
-#endif
-			break;
+	unit_m4(ModelView3D);
 #if SUPPORT_LEGACY_MATRIX
-		case MATRIX_MODE_INACTIVE:
-			glLoadIdentity();
-			break;
+	glLoadIdentity();
 #endif
-		default:
-			BLI_assert(false);
-	}
 	state.dirty = true;
 }
 
 void gpuTranslate2f(float x, float y)
 {
 #if SUPPORT_LEGACY_MATRIX
-	if (state.mode == MATRIX_MODE_INACTIVE) {
+	{
 		glTranslatef(x, y, 0.0f);
 		state.dirty = true;
 		return;
 	}
 #endif
 
-#if MATRIX_2D_4x4
 	Mat4 m;
 	unit_m4(m);
 	m[3][0] = x;
 	m[3][1] = y;
-#else
-	Mat3 m;
-	unit_m3(m);
-	m[2][0] = x;
-	m[2][1] = y;
-#endif
 	gpuMultMatrix2D(m);
 }
 
@@ -284,14 +219,13 @@ void gpuTranslate2fv(const float vec[2])
 void gpuTranslate3f(float x, float y, float z)
 {
 #if SUPPORT_LEGACY_MATRIX
-	if (state.mode == MATRIX_MODE_INACTIVE) {
+	{
 		glTranslatef(x, y, z);
 		state.dirty = true;
 		return;
 	}
 #endif
 
-	BLI_assert(state.mode == MATRIX_MODE_3D);
 #if 1
 	translate_m4(ModelView3D, x, y, z);
 	CHECKMAT(ModelView3D);
@@ -313,64 +247,31 @@ void gpuTranslate3fv(const float vec[3])
 
 void gpuScaleUniform(float factor)
 {
-	switch (state.mode) {
-		case MATRIX_MODE_3D:
-		{
-			Mat4 m;
-			scale_m4_fl(m, factor);
-			gpuMultMatrix3D(m);
-			break;
-		}
-		case MATRIX_MODE_2D:
-		{
-#if MATRIX_2D_4x4
-			Mat4 m = {{0.0f}};
-			m[0][0] = factor;
-			m[1][1] = factor;
-			m[2][2] = 1.0f;
-			m[3][3] = 1.0f;
-#else
-			Mat3 m = {{0.0f}};
-			m[0][0] = factor;
-			m[1][1] = factor;
-			m[2][2] = 1.0f;
-#endif
-			gpuMultMatrix2D(m);
-			break;
-		}
+	Mat4 m;
+	scale_m4_fl(m, factor);
+	gpuMultMatrix3D(m);
+
 #if SUPPORT_LEGACY_MATRIX
-		case MATRIX_MODE_INACTIVE:
-			glScalef(factor, factor, factor); /* always scale Z since we can't distinguish 2D from 3D */
-			state.dirty = true;
-			break;
+	glScalef(factor, factor, factor); /* always scale Z since we can't distinguish 2D from 3D */
+	state.dirty = true;
 #endif
-		default:
-			BLI_assert(false);
-	}
 }
 
 void gpuScale2f(float x, float y)
 {
 #if SUPPORT_LEGACY_MATRIX
-	if (state.mode == MATRIX_MODE_INACTIVE) {
+	{
 		glScalef(x, y, 1.0f);
 		state.dirty = true;
 		return;
 	}
 #endif
 
-#if MATRIX_2D_4x4
 	Mat4 m = {{0.0f}};
 	m[0][0] = x;
 	m[1][1] = y;
 	m[2][2] = 1.0f;
 	m[3][3] = 1.0f;
-#else
-	Mat3 m = {{0.0f}};
-	m[0][0] = x;
-	m[1][1] = y;
-	m[2][2] = 1.0f;
-#endif
 	gpuMultMatrix2D(m);
 }
 
@@ -382,7 +283,7 @@ void gpuScale2fv(const float vec[2])
 void gpuScale3f(float x, float y, float z)
 {
 #if SUPPORT_LEGACY_MATRIX
-	if (state.mode == MATRIX_MODE_INACTIVE) {
+	{
 		glScalef(x, y, z);
 		state.dirty = true;
 		return;
@@ -405,14 +306,13 @@ void gpuScale3fv(const float vec[3])
 void gpuMultMatrix3D(const float m[4][4])
 {
 #if SUPPORT_LEGACY_MATRIX
-	if (state.mode == MATRIX_MODE_INACTIVE) {
+	{
 		glMultMatrixf((const float*) m);
 		state.dirty = true;
 		return;
 	}
 #endif
 
-	BLI_assert(state.mode == MATRIX_MODE_3D);
 	mul_m4_m4_post(ModelView3D, m);
 	CHECKMAT(ModelView3D);
 	state.dirty = true;
@@ -421,15 +321,13 @@ void gpuMultMatrix3D(const float m[4][4])
 #if MATRIX_2D_4x4
 void gpuMultMatrix2D(const float m[4][4])
 {
-	BLI_assert(state.mode == MATRIX_MODE_2D);
-	mul_m4_m4_post(ModelView2D, m);
+	mul_m4_m4_post(ModelView3D, m);
 	CHECKMAT(ModelView2D);
 	state.dirty = true;
 }
 #else
 void gpuMultMatrix2D(const float m[3][3])
 {
-	BLI_assert(state.mode == MATRIX_MODE_2D);
 	mul_m3_m3_post(ModelView2D, m);
 	CHECKMAT(ModelView2D);
 	state.dirty = true;
@@ -439,21 +337,17 @@ void gpuMultMatrix2D(const float m[3][3])
 void gpuRotate2D(float deg)
 {
 #if SUPPORT_LEGACY_MATRIX
-	if (state.mode == MATRIX_MODE_INACTIVE) {
+	{
 		glRotatef(deg, 0.0f, 0.0f, 1.0f);
 		state.dirty = true;
 		return;
 	}
 #endif
 
-#if MATRIX_2D_4x4
 	/* essentially RotateAxis('Z')
 	 * TODO: simpler math for 2D case
 	 */
-	rotate_m4(ModelView2D, 'Z', DEG2RADF(deg));
-#else
-	BLI_assert(false); /* TODO: finish for MATRIX_MODE_2D */
-#endif
+	rotate_m4(ModelView3D, 'Z', DEG2RADF(deg));
 }
 
 void gpuRotate3f(float deg, float x, float y, float z)
@@ -465,7 +359,7 @@ void gpuRotate3f(float deg, float x, float y, float z)
 void gpuRotate3fv(float deg, const float axis[3])
 {
 #if SUPPORT_LEGACY_MATRIX
-	if (state.mode == MATRIX_MODE_INACTIVE) {
+	{
 		glRotatef(deg, axis[0], axis[1], axis[2]);
 		state.dirty = true;
 		return;
@@ -480,7 +374,7 @@ void gpuRotate3fv(float deg, const float axis[3])
 void gpuRotateAxis(float deg, char axis)
 {
 #if SUPPORT_LEGACY_MATRIX
-	if (state.mode == MATRIX_MODE_INACTIVE) {
+	{
 		float a[3] = { 0.0f };
 		switch (axis) {
 			case 'X': a[0] = 1.0f; break;
@@ -494,7 +388,6 @@ void gpuRotateAxis(float deg, char axis)
 	}
 #endif
 
-	BLI_assert(state.mode == MATRIX_MODE_3D);
 	/* rotate_m4 works in place */
 	rotate_m4(ModelView3D, axis, DEG2RADF(deg));
 	CHECKMAT(ModelView3D);
@@ -620,7 +513,7 @@ static void mat4_look_from_origin(float m[4][4], float lookdir[3], float camup[3
 void gpuOrtho(float left, float right, float bottom, float top, float near, float far)
 {
 #if SUPPORT_LEGACY_MATRIX
-	if (state.mode == MATRIX_MODE_INACTIVE) {
+	{
 		GLenum mode;
 		glGetIntegerv(GL_MATRIX_MODE, (GLint*)&mode);
 		if (mode != GL_PROJECTION) {
@@ -639,7 +532,6 @@ void gpuOrtho(float left, float right, float bottom, float top, float near, floa
 	}
 #endif
 
-	BLI_assert(state.mode == MATRIX_MODE_3D);
 	mat4_ortho_set(Projection3D, left, right, bottom, top, near, far);
 	CHECKMAT(Projection3D);
 	state.dirty = true;
@@ -648,7 +540,7 @@ void gpuOrtho(float left, float right, float bottom, float top, float near, floa
 void gpuOrtho2D(float left, float right, float bottom, float top)
 {
 #if SUPPORT_LEGACY_MATRIX
-	if (state.mode == MATRIX_MODE_INACTIVE) {
+	{
 		GLenum mode;
 		glGetIntegerv(GL_MATRIX_MODE, (GLint*)&mode);
 		if (mode != GL_PROJECTION) {
@@ -667,13 +559,8 @@ void gpuOrtho2D(float left, float right, float bottom, float top)
 	}
 #endif
 
-	BLI_assert(state.mode == MATRIX_MODE_2D);
-#if MATRIX_2D_4x4
 	Mat4 m;
 	mat4_ortho_set(m, left, right, bottom, top, -1.0f, 1.0f);
-#else
-	/* TODO: correct 3x3 implementation */
-#endif
 	CHECKMAT(Projection2D);
 	state.dirty = true;
 }
@@ -681,7 +568,7 @@ void gpuOrtho2D(float left, float right, float bottom, float top)
 void gpuFrustum(float left, float right, float bottom, float top, float near, float far)
 {
 #if SUPPORT_LEGACY_MATRIX
-	if (state.mode == MATRIX_MODE_INACTIVE) {
+	{
 		GLenum mode;
 		glGetIntegerv(GL_MATRIX_MODE, (GLint*)&mode);
 		if (mode != GL_PROJECTION) {
@@ -700,7 +587,6 @@ void gpuFrustum(float left, float right, float bottom, float top, float near, fl
 	}
 #endif
 
-	BLI_assert(state.mode == MATRIX_MODE_3D);
 	mat4_frustum_set(Projection3D, left, right, bottom, top, near, far);
 	CHECKMAT(Projection3D);
 	state.dirty = true;
@@ -786,7 +672,7 @@ bool gpuUnProject(const float win[3], const float model[4][4], const float proj[
 const float *gpuGetModelViewMatrix3D(float m[4][4])
 {
 #if SUPPORT_LEGACY_MATRIX
-	if (state.mode == MATRIX_MODE_INACTIVE) {
+	{
 		if (m == NULL) {
 			static Mat4 temp;
 			m = temp;
@@ -797,8 +683,6 @@ const float *gpuGetModelViewMatrix3D(float m[4][4])
 	}
 #endif
 
-	BLI_assert(state.mode == MATRIX_MODE_3D);
-
 	if (m) {
 		copy_m4_m4(m, ModelView3D);
 		return (const float*)m;
@@ -811,7 +695,7 @@ const float *gpuGetModelViewMatrix3D(float m[4][4])
 const float *gpuGetProjectionMatrix3D(float m[4][4])
 {
 #if SUPPORT_LEGACY_MATRIX
-	if (state.mode == MATRIX_MODE_INACTIVE) {
+	{
 		if (m == NULL) {
 			static Mat4 temp;
 			m = temp;
@@ -822,8 +706,6 @@ const float *gpuGetProjectionMatrix3D(float m[4][4])
 	}
 #endif
 
-	BLI_assert(state.mode == MATRIX_MODE_3D);
-
 	if (m) {
 		copy_m4_m4(m, Projection3D);
 		return (const float*)m;
@@ -841,7 +723,7 @@ const float *gpuGetModelViewProjectionMatrix3D(float m[4][4])
 	}
 
 #if SUPPORT_LEGACY_MATRIX
-	if (state.mode == MATRIX_MODE_INACTIVE) {
+	{
 		Mat4 proj;
 		glGetFloatv(GL_MODELVIEW_MATRIX, (float*)m);
 		glGetFloatv(GL_PROJECTION_MATRIX, (float*)proj);
@@ -850,8 +732,6 @@ const float *gpuGetModelViewProjectionMatrix3D(float m[4][4])
 	}
 #endif
 
-	BLI_assert(state.mode == MATRIX_MODE_3D);
-
 	mul_m4_m4m4(m, Projection3D, ModelView3D);
 	return (const float*)m;
 }
@@ -884,49 +764,6 @@ const float *gpuGetNormalMatrixInverse(float m[3][3])
 	return (const float*)m;
 }
 
-#if MATRIX_2D_4x4
-static const float *gpuGetModelViewMatrix2D(float m[4][4])
-{
-	BLI_assert(state.mode == MATRIX_MODE_2D);
-
-	if (m) {
-		copy_m4_m4(m, ModelView2D);
-		return (const float*)m;
-	}
-	else {
-		return (const float*)ModelView2D;
-	}
-}
-
-static const float *gpuGetProjectionMatrix2D(float m[4][4])
-{
-	BLI_assert(state.mode == MATRIX_MODE_2D);
-
-	if (m) {
-		copy_m4_m4(m, Projection2D);
-		return (const float*)m;
-	}
-	else {
-		return (const float*)Projection2D;
-	}
-}
-
-static const float *gpuGetModelViewProjectionMatrix2D(float m[4][4])
-{
-	BLI_assert(state.mode == MATRIX_MODE_2D);
-
-	if (m == NULL) {
-		static Mat4 temp;
-		m = temp;
-	}
-
-	mul_m4_m4m4(m, Projection2D, ModelView2D);
-	return (const float*)m;
-}
-#else /* not MATRIX_2D_4x4 */
-/* TODO: implement 3x3 getters */
-#endif
-
 void gpuBindMatrices(const ShaderInterface* shaderface)
 {
 	/* set uniform values to matrix stack values
@@ -937,83 +774,55 @@ void gpuBindMatrices(const ShaderInterface* shaderface)
 	const ShaderInput *MV = ShaderInterface_builtin_uniform(shaderface, UNIFORM_MODELVIEW_3D);
 	const ShaderInput *P = ShaderInterface_builtin_uniform(shaderface, UNIFORM_PROJECTION_3D);
 	const ShaderInput *MVP = ShaderInterface_builtin_uniform(shaderface, UNIFORM_MVP_3D);
-	/* TODO: teach ShaderInterface to distinguish 2D from 3D --^ */
-
-	if (state.mode == MATRIX_MODE_2D) {
-		if (MV) {
-			#if DEBUG_MATRIX_BIND
-			puts("setting 2D MV matrix");
-			#endif
 
-			glUniformMatrix4fv(MV->location, 1, GL_FALSE, gpuGetModelViewMatrix2D(NULL));
-		}
+	const ShaderInput *N = ShaderInterface_builtin_uniform(shaderface, UNIFORM_NORMAL_3D);
+	const ShaderInput *MV_inv = ShaderInterface_builtin_uniform(shaderface, UNIFORM_MODELVIEW_INV_3D);
+	const ShaderInput *P_inv = ShaderInterface_builtin_uniform(shaderface, UNIFORM_PROJECTION_INV_3D);
 
-		if (P) {
-			#if DEBUG_MATRIX_BIND
-			puts("setting 2D P matrix");
-			#endif
+	if (MV) {
+		#if DEBUG_MATRIX_BIND
+		puts("setting 3D MV matrix");
+		#endif
 
-			glUniformMatrix4fv(P->location, 1, GL_FALSE, gpuGetProjectionMatrix2D(NULL));
-		}
-
-		if (MVP) {
-			#if DEBUG_MATRIX_BIND
-			puts("setting 2D MVP matrix");
-			#endif
-
-			glUniformMatrix4fv(MVP->location, 1, GL_FALSE, gpuGetModelViewProjectionMatrix2D(NULL));
-		}
+		glUniformMatrix4fv(MV->location, 1, GL_FALSE, gpuGetModelViewMatrix3D(NULL));
 	}
-	else {
-		const ShaderInput *N = ShaderInterface_builtin_uniform(shaderface, UNIFORM_NORMAL_3D);
-		const ShaderInput *MV_inv = ShaderInterface_builtin_uniform(shaderface, UNIFORM_MODELVIEW_INV_3D);
-		const ShaderInput *P_inv = ShaderInterface_builtin_uniform(shaderface, UNIFORM_PROJECTION_INV_3D);
-
-		if (MV) {
-			#if DEBUG_MATRIX_BIND
-			puts("setting 3D MV matrix");
-			#endif
-
-			glUniformMatrix4fv(MV->location, 1, GL_FALSE, gpuGetModelViewMatrix3D(NULL));
-		}
 
-		if (P) {
-			#if DEBUG_MATRIX_BIND
-			puts("setting 3D P matrix");
-			#endif
+	if (P) {
+		#if DEBUG_MATRIX_BIND
+		puts("setting 3D P matrix");
+		#endif
 
-			glUniformMatrix4fv(P->location, 1, GL_FALSE, gpuGetProjectionMatrix3D(NULL));
-		}
+		glUniformMatrix4fv(P->location, 1, GL_FALSE, gpuGetProjectionMatrix3D(NULL));
+	}
 
-		if (MVP) {
-			#if DEBUG_MATRIX_BIND
-			puts("setting 3D MVP matrix");
-			#endif
+	if (MVP) {
+		#if DEBUG_MATRIX_BIND
+		puts("setting 3D MVP matrix");
+		#endif
 
-			glUniformMatrix4fv(MVP->location, 1, GL_FALSE, gpuGetModelViewProjectionMatrix3D(NULL));
-		}
+		glUniformMatrix4fv(MVP->location, 1, GL_FALSE, gpuGetModelViewProjectionMatrix3D(NULL));
+	}
 
-		if (N) {
-			#if DEBUG_MATRIX_BIND
-			puts("setting 3D normal matrix");
-			#endif
+	if (N) {
+		#if DEBUG_MATRIX_BIND
+		puts("setting 3D normal matrix");
+		#endif
 
-			glUniformMatrix3fv(N->location, 1, GL_FALSE, gpuGetNormalMatrix(NULL));
-		}
+		glUniformMatrix3fv(N->location, 1, GL_FALSE, gpuGetNormalMatrix(NULL));
+	}
 
-		if (MV_inv) {
-			Mat4 m;
-			gpuGetModelViewMatrix3D(m);
-			invert_m4(m);
-			glUniformMatrix4fv(MV_inv->location, 1, GL_FALSE, (const float*) m);
-		}
+	if (MV_inv) {
+		Mat4 m;
+		gpuGetModelViewMatrix3D(m);
+		invert_m4(m);
+		glUniformMatrix4fv(MV_inv->location, 1, GL_FALSE, (const float*) m);
+	}
 
-		if (P_inv) {
-			Mat4 m;
-			gpuGetProjectionMatrix3D(m);
-			invert_m4(m);
-			glUniformMatrix4fv(P_inv->location, 1, GL_FALSE, (const float*) m);
-		}
+	if (P_inv) {
+		Mat4 m;
+		gpuGetProjectionMatrix3D(m);
+		invert_m4(m);
+		glUniformMatrix4fv(P_inv->location, 1, GL_FALSE, (const float*) m);
 	}
 
 	state.dirty = false;