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blender/source/blender/gpu/opengl/gl_state.cc

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C++

/*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software Foundation,
* Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*
* Copyright 2020, Blender Foundation.
*/
/** \file
* \ingroup gpu
*/
#include "BLI_math_base.h"
#include "GPU_extensions.h"
#include "glew-mx.h"
#include "gl_state.hh"
using namespace blender::gpu;
/* -------------------------------------------------------------------- */
/** \name GLStateManager
* \{ */
void GLStateManager::set_state(const GPUState &state)
{
GPUState changed = state ^ current_;
if (changed.blend != 0) {
set_blend(state.blend);
}
if (changed.write_mask != 0) {
set_write_mask(state.write_mask);
}
if (changed.depth_test != 0) {
set_depth_test(state.depth_test);
}
if (changed.stencil_test != 0 || changed.stencil_op != 0) {
set_stencil_test(state.stencil_test, state.stencil_op);
set_stencil_mask(state.stencil_test, mutable_state);
}
if (changed.clip_distances != 0) {
set_clip_distances(state.clip_distances, current_.clip_distances);
}
if (changed.culling_test != 0) {
set_backface_culling(state.culling_test);
}
if (changed.logic_op_xor != 0) {
set_logic_op(state.logic_op_xor);
}
if (changed.invert_facing != 0) {
set_facing(state.invert_facing);
}
if (changed.provoking_vert != 0) {
set_provoking_vert(state.provoking_vert);
}
if (changed.shadow_bias != 0) {
set_shadow_bias(state.shadow_bias);
}
/* TODO remove */
if (changed.polygon_smooth) {
if (state.polygon_smooth) {
glEnable(GL_POLYGON_SMOOTH);
}
else {
glDisable(GL_POLYGON_SMOOTH);
}
}
if (changed.line_smooth) {
if (state.line_smooth) {
glEnable(GL_LINE_SMOOTH);
}
else {
glDisable(GL_LINE_SMOOTH);
}
}
current_ = state;
}
void GLStateManager::set_mutable_state(const GPUStateMutable &state)
{
GPUStateMutable changed = state ^ current_mutable_;
if ((changed.viewport_rect[0] != 0) || (changed.viewport_rect[1] != 0) ||
(changed.viewport_rect[2] != 0) || (changed.viewport_rect[3] != 0)) {
glViewport(UNPACK4(state.viewport_rect));
}
if ((changed.scissor_rect[0] != 0) || (changed.scissor_rect[1] != 0) ||
(changed.scissor_rect[2] != 0) || (changed.scissor_rect[3] != 0)) {
glScissor(UNPACK4(state.scissor_rect));
if ((state.scissor_rect[2] > 0)) {
glEnable(GL_SCISSOR_TEST);
}
else {
glDisable(GL_SCISSOR_TEST);
}
}
/* TODO remove, should be uniform. */
if (changed.point_size != 0) {
if (state.point_size > 0.0f) {
glEnable(GL_PROGRAM_POINT_SIZE);
glPointSize(state.point_size);
}
else {
glDisable(GL_PROGRAM_POINT_SIZE);
}
}
if (changed.line_width != 0) {
/* TODO remove, should use wide line shader. */
glLineWidth(clamp_f(state.line_width, 1.0f, GPU_max_line_width()));
}
if (changed.depth_range[0] != 0 || changed.depth_range[1] != 0) {
/* TODO remove, should modify the projection matrix instead. */
glDepthRange(UNPACK2(state.depth_range));
}
if (changed.stencil_compare_mask != 0 || changed.stencil_reference != 0 ||
changed.stencil_write_mask != 0) {
set_stencil_mask(current_.stencil_test, state);
}
current_mutable_ = state;
}
/** \} */
/* -------------------------------------------------------------------- */
/** \name State set functions
* \{ */
void GLStateManager::set_write_mask(const eGPUWriteMask value)
{
glDepthMask((value & GPU_WRITE_DEPTH) != 0);
glColorMask((value & GPU_WRITE_RED) != 0,
(value & GPU_WRITE_GREEN) != 0,
(value & GPU_WRITE_BLUE) != 0,
(value & GPU_WRITE_ALPHA) != 0);
}
void GLStateManager::set_depth_test(const eGPUDepthTest value)
{
GLenum func;
switch (value) {
case GPU_DEPTH_LESS:
func = GL_LESS;
break;
case GPU_DEPTH_LESS_EQUAL:
func = GL_LEQUAL;
break;
case GPU_DEPTH_EQUAL:
func = GL_EQUAL;
break;
case GPU_DEPTH_GREATER:
func = GL_GREATER;
break;
case GPU_DEPTH_GREATER_EQUAL:
func = GL_GEQUAL;
break;
case GPU_DEPTH_ALWAYS:
default:
func = GL_ALWAYS;
break;
}
if (value != GPU_DEPTH_NONE) {
glEnable(GL_DEPTH_TEST);
glDepthFunc(func);
}
else {
glDisable(GL_DEPTH_TEST);
}
}
void GLStateManager::set_stencil_test(const eGPUStencilTest test, const eGPUStencilOp operation)
{
switch (operation) {
case GPU_STENCIL_OP_REPLACE:
glStencilOp(GL_KEEP, GL_KEEP, GL_REPLACE);
break;
case GPU_STENCIL_OP_COUNT_DEPTH_PASS:
glStencilOpSeparate(GL_BACK, GL_KEEP, GL_KEEP, GL_INCR_WRAP);
glStencilOpSeparate(GL_FRONT, GL_KEEP, GL_KEEP, GL_DECR_WRAP);
break;
case GPU_STENCIL_OP_COUNT_DEPTH_FAIL:
glStencilOpSeparate(GL_BACK, GL_KEEP, GL_DECR_WRAP, GL_KEEP);
glStencilOpSeparate(GL_FRONT, GL_KEEP, GL_INCR_WRAP, GL_KEEP);
break;
case GPU_STENCIL_OP_NONE:
default:
glStencilOp(GL_KEEP, GL_KEEP, GL_KEEP);
}
if (test != GPU_STENCIL_NONE) {
glEnable(GL_STENCIL_TEST);
}
else {
glDisable(GL_STENCIL_TEST);
}
}
void GLStateManager::set_stencil_mask(const eGPUStencilTest test, const GPUStateMutable state)
{
GLenum func;
switch (test) {
case GPU_STENCIL_NEQUAL:
func = GL_NOTEQUAL;
break;
case GPU_STENCIL_EQUAL:
func = GL_EQUAL;
break;
case GPU_STENCIL_ALWAYS:
func = GL_ALWAYS;
break;
case GPU_STENCIL_NONE:
default:
glStencilMask(0x00);
glStencilFunc(GL_ALWAYS, 0x00, 0x00);
return;
}
glStencilMask(state.stencil_write_mask);
glStencilFunc(func, state.stencil_reference, state.stencil_compare_mask);
}
void GLStateManager::set_clip_distances(const int new_dist_len, const int old_dist_len)
{
for (int i = 0; i < new_dist_len; i++) {
glEnable(GL_CLIP_DISTANCE0 + i);
}
for (int i = new_dist_len; i < old_dist_len; i++) {
glDisable(GL_CLIP_DISTANCE0 + i);
}
}
void GLStateManager::set_logic_op(const bool enable)
{
if (enable) {
glEnable(GL_COLOR_LOGIC_OP);
glLogicOp(GL_XOR);
}
else {
glDisable(GL_COLOR_LOGIC_OP);
}
}
void GLStateManager::set_facing(const bool invert)
{
glFrontFace((invert) ? GL_CW : GL_CCW);
}
void GLStateManager::set_backface_culling(const eGPUFaceCullTest test)
{
if (test != GPU_CULL_NONE) {
glDisable(GL_CULL_FACE);
}
else {
glEnable(GL_CULL_FACE);
glCullFace((test == GPU_CULL_FRONT) ? GL_FRONT : GL_BACK);
}
}
void GLStateManager::set_provoking_vert(const eGPUProvokingVertex vert)
{
GLenum value = (vert == GPU_VERTEX_FIRST) ? GL_FIRST_VERTEX_CONVENTION :
GL_LAST_VERTEX_CONVENTION;
glProvokingVertex(value);
}
void GLStateManager::set_shadow_bias(const bool enable)
{
if (enable) {
glEnable(GL_POLYGON_OFFSET_FILL);
glEnable(GL_POLYGON_OFFSET_LINE);
/* 2.0 Seems to be the lowest possible slope bias that works in every case. */
glPolygonOffset(2.0f, 1.0f);
}
else {
glDisable(GL_POLYGON_OFFSET_FILL);
glDisable(GL_POLYGON_OFFSET_LINE);
}
}
void GLStateManager::set_blend(const eGPUBlend value)
{
/**
* Factors to the equation.
* SRC is fragment shader output.
* DST is framebuffer color.
* final.rgb = SRC.rgb * src_rgb + DST.rgb * dst_rgb;
* final.a = SRC.a * src_alpha + DST.a * dst_alpha;
**/
GLenum src_rgb, src_alpha, dst_rgb, dst_alpha;
switch (value) {
default:
case GPU_BLEND_ALPHA: {
src_rgb = GL_SRC_ALPHA;
dst_rgb = GL_ONE_MINUS_SRC_ALPHA;
src_alpha = GL_ONE;
dst_alpha = GL_ONE_MINUS_SRC_ALPHA;
break;
}
case GPU_BLEND_ALPHA_PREMULT: {
src_rgb = GL_ONE;
dst_rgb = GL_ONE_MINUS_SRC_ALPHA;
src_alpha = GL_ONE;
dst_alpha = GL_ONE_MINUS_SRC_ALPHA;
break;
}
case GPU_BLEND_ADDITIVE: {
/* Do not let alpha accumulate but premult the source RGB by it. */
src_rgb = GL_SRC_ALPHA;
dst_rgb = GL_ONE;
src_alpha = GL_ZERO;
dst_alpha = GL_ONE;
break;
}
case GPU_BLEND_SUBTRACT:
case GPU_BLEND_ADDITIVE_PREMULT: {
/* Let alpha accumulate. */
src_rgb = GL_ONE;
dst_rgb = GL_ONE;
src_alpha = GL_ONE;
dst_alpha = GL_ONE;
break;
}
case GPU_BLEND_MULTIPLY: {
src_rgb = GL_DST_COLOR;
dst_rgb = GL_ZERO;
src_alpha = GL_DST_ALPHA;
dst_alpha = GL_ZERO;
break;
}
case GPU_BLEND_INVERT: {
src_rgb = GL_ONE_MINUS_DST_COLOR;
dst_rgb = GL_ZERO;
src_alpha = GL_ZERO;
dst_alpha = GL_ONE;
break;
}
case GPU_BLEND_OIT: {
src_rgb = GL_ONE;
dst_rgb = GL_ONE;
src_alpha = GL_ZERO;
dst_alpha = GL_ONE_MINUS_SRC_ALPHA;
break;
}
case GPU_BLEND_BACKGROUND: {
src_rgb = GL_ONE_MINUS_DST_ALPHA;
dst_rgb = GL_SRC_ALPHA;
src_alpha = GL_ZERO;
dst_alpha = GL_SRC_ALPHA;
break;
}
case GPU_BLEND_CUSTOM: {
src_rgb = GL_ONE;
dst_rgb = GL_SRC1_COLOR;
src_alpha = GL_ONE;
dst_alpha = GL_SRC1_ALPHA;
break;
}
}
if (value != GPU_BLEND_NONE) {
glBlendFuncSeparate(src_rgb, dst_rgb, src_alpha, dst_alpha);
glEnable(GL_BLEND);
}
else {
glDisable(GL_BLEND);
}
}
/** \} */